Forging

FORGING AMERICAN SCHOOL

째f CORRESPONDENCE

CHICAGO TT 2.15

U. S.

ILLINOIS A.

Class

T'

;

\

_

'

Book

.

h

5

Copyright N째. COPYRIGHT DEPOSIT.

FORGING

INSTRUCTION PAPER PREPARED BY

John Lord Bacon Work

Instructor in Forge

Lewis Institute

American Society of Mechanical Engineers

Author of "Forge Practice"

AMERICAN SCHOOL, OF CORRESPONDENCE U.S.A.

ILLINOIS

$ .*

LIBRARY

Two

of

CONGRESS

Copies Received

APR 23 1906

BLASS

OPY

B.

Copyright 1906 by American School of Correspondence Entered at Stationers' Hall, London All Rights Reserved

FORGING.

3f

Forging in general treats of the hammering, working, or forming heated metals.

The Materials upon which the work of forging or blacksmithdone, are wrought iron and steel. As explained in "Metallurgy," wrought iron is an iron from which "the silicon phosphorus ing

is

and most of the carbon has been removed." Steel usually contains some of the impurities that are characteristic of cast iron with the

marked

Mild

peculiarity of holding a varying percentage of carbon.

steels are so called

comes more

difficult to

used in heating Until recently

wrought

lest all

iron, but

on account of the small amount of carbon

As the percentage

which they contain.

of carbon increases,

weld the metal.

it

be-

Greater care must also be

the metal be burned and

its

strength destroyed.

heavy forgings involving welding, were made of

now

customary

it is

to

make most

forgings of mild

wrought iron

is somewhat more satisfactory where a great amount of welding is required. These metals may be roughly divided into three general classes; although the. division line may not be sharply drawn between any two classes, the classes being Wrought Iron, Machine Steel and Tool Steel. The characteristics and method of manufacture of the three

particularly large ones, although

steel,

metals are described in "Metallurgy." a blacksmith would use

is

A

rough distinction such as

about as follows:

Wrought Iron has a

fibrous structure with stringy streaks of slag running lengthwise of

the bar giving

it a decided fibre, similar to wood. Machine Steel, more properly described as mild steel, or sometimes called soft steel, has much the same properties as wrought iron excepting that it lacks the fibre and is somewhat stronger. Tool Steel differs from the

other two materials in the fact that by suddenly cooling from a high

heat

it

may

Wrought ment.

be made very hard, or hardens, as the technical term

iron or

Tool

machine

steel are

steel is practically the

is.

not hardened by the same treat-

same thing

as wrought iron or

FORGING machine

with a small percentage of carbon added.

steel

either of the

two metals may be turned

of carbon.

This principle

or Swedish iron

is

In

fact,

by the addition

into tool steel

Norway

used in case hardening.

iron

a grade of very pure wrought iron containing

is

slag. It is

little

more expensive

than

ordinary wrought

iron..

Refined iron

is

a

wrought iron

grade of

Norway

not as good as

iron but better than or-

dinary iron.

V.,

Norway

iron costs about twice as v.T". ;

,

much

y ': 7. ;;-,:.

Fig.

cheaper

any grade.

iron of almost

Machine

hearth and Bessemer processes,

is

steel,

machine

as

which

1.

is

steel,

somewhat

than

made by both

wrought the open-

used for forging.

EQUIPMENT. The equipment of the forge shop consists in general of a forge which the metals are heated, an anvil for resting the metals on while hammering, and the

in

various tools as

below

described

shaping

for

and

working.

The Forge. While or fires are of

and

sizes

many

shapes

the principles of

their

construction

the

same.

An

blacksmith forge

place

forges

the

in

which there

is

remain ordinary a

is

fire-

bottom of

a tuyere for

admitting a blast of air to

blow the

fire.

Where

air blast is furnished

the tuyere

is

Fig.

2.

the

by a hand bellows, the pipe leading therefrom

open throughout.

ishes the blast, there

is

Where a power-driven blower

a valve in the pipe for regulating

the*

to

furn-

same.

FOKGING The

usual form of tuyere consists of a single blast pipe, open-

This may be a simple nozzle as by a damper in the pipe; or, it may have a regulator at the mouth of the tuyere as shown. Sometimes the tuyere has several openings, and is then in the form of a ing into the bottom of the

fire pit.

in Fig. 1, with the blast regulated

jSjaggBB^"^

Fig. 3.

grate.

Whatever

its

form,

it

should be possible to clean

it

from be-

and clinkers falling into it may be removed. modern type of forge is shown in Fig. 2. This is provided with a hood for carrying off the smoke. The pipe connected to the hood extends downward to an underground flue leading to an exlow, in order- that coal

A

haust fan which draws out the

air.

The

blast pipe

is

also under-

FORGING ground, and a small pipe leads upward to the tuyere, the amount of blast admitted to the fire being regulated

This system of underground piping

is

by a

this pipe.

slide in

"Down

Draft"

for carrying off the

smoke,

known

as the

system.

In some shops no provision

is

made

while in others hoods are placed above the forges and connected to

overhead pipes, which led directly to the roof.

may be either connected to an exhaust fan or The "Down Draft" system is the more mod-

ern and generally the best.

The

Blast

is

furnished to the

of various kinds.

fires

of a blacksmith shop

This has been superseded by the fan blower which universally used, even for hand power.

Such a fan blower is shown in cast-iron shell in which there are a These blades

of

the

up a current

Fig. 3.

It is

is

now

almost

formed of a thin

set of rapidly revolving blades.

which presses against the side

of air

The and escapes through the tangential opening. from fire varies blacksmith open the blast used for an

shell

pressure of

about 2

set

by blowers

For many years the ordinary bellows was used.

to 7

for

a light

for

heavy

ounces per square inch.

fire

and

light

work.

The

The

lower pressure

higher pressure

is

used

suitable

is

classes of work.

Hammers. Several kinds of hammers are used in a forge shop. The commonest shape is the ball pene shown at A, Fig. 4. Other kinds are the straight pene and cross pene illustrated at

B and

A

hammer,

square faced

hammer sometimes

called a blacksmith's

This is occasionally used on shown at D. monly a ball pene hammer of about a pound and a

is

tool

Com-

work.

half weight

C.

is

used.

FORGING In the

major

fitting of

Hammer

taken.

the handle to the head great care

made

handles are

should be

The

elliptical in cross section.

axis of this ellipse should exactly coincide with that of the

The

eye of the head.

handle so that

its

major

reason

is

that the

hand naturally grasps the

axis lies in the direction of the line of motion.

Hence, unless the handle

is

properly

fitted in this particular, there

The handle

will be constant danger of striking a glancing blow.

should also stand at right angles to a center line drawn from the ball

The

of the pene to the face.

weight on the face side of this

is

is

eye in the head

if

usually so set that the

greater than that on the pene.

The

effect

and more accurate blows

to so balance the tool that heavier

can be struck than

is

the weight were evenly balanced on each side

of the eye.

Sledges are heavier

and vary

in

weight from

hammers used by five to

shapes are shown in Fig. 5; A, B, and

and double faced sledges

the blacksmith's

twenty pounds.

C

respectively.

ordinarily weighs about 12 pounds.

The

three

helper

common

being cross pene, straight pene

A

sledge for

common work

Sledge handles are generally

about 30 to 36 inches long, depending on the nature of the work to

be done.

hammer

the anvil.

This

be any block of metal upon which the piece to be shaped

is laid.

Anvils.

may The

Next

to the

in

importance

is

must be of such a weight that it can absorb the blows that are struck upon it without experiencing any perceptible motion anvil

in itself.

for

The ordinary many hundreds

has remained unchanged in form As now made, the body a is of wrought

anvil, Fig. 6,

of years.

FORGING

6

which a face of hardened

iron to

steel is

welded.

From one end

and the overhang of the body at the other At the bottom there are four projections d, called the feet, which serve to increase the base upon which the anvil rests as well as to afford the means for clamping it down into position.

there projects the horn

end

c, is

In the

b,

called the tail.

tail

there

is

a square and a circular hole.

called the hardie hole, the latter the

An may be

anvil of this

The former

is

hole.

for the execution of

any work that

desired.

Anvils are also of steel

form serves

spud

is

made with

a body of cast iron, to which a face

welded.

The anvil should be placed upon the end of a heavy block of wood sunken into the ground to a depth of at least two feet, so that it may rest upon a firm but elastic foundation. As the anvil is sub-

Fig. 6.

jected to constant vibrations,

that

it

by the nature of the work,

it is

necessary

should be firmly fastened to the block.

Anvils are classed and sold by weight.

The

weight

is

generally

stamped on the side of the anvil. Three numbers are used. first to the left shows the weight in cwt. of 112 pounds each.

The The

middle number shows the additional quarters of cwt. and the right

hand figure the number of odd pounds. For instance, an anvil marked 2-3-4 would weigh 2X112 + f of 112 + 4 lbs. =312 lbs. and would be known as about a 300-pound anvil. Anvils are sometimes made of special shapes, but the one here shown is the common one. Tongs. Next to the hammer and anvil in importance and usage are the tongs.

They vary

in size

from those suitable

for hold-

FORGING ing the smallest wires to those capable of handling ingots and bars of

many

tons in weight.

piece to be handled

The jaws

are also adapted to

fit

over the

and are of a great variety of shapes.

As the

Fig. 7.

requirements of each piece of work varies so

much from that which customary for the blacksmith to dress own tongs and adapt them, from time to time, to the work he

precedes and follows his

it,

it is

has in hand.

Comparatively few, therefore, of the various shapes of tongs found in shops are manufactured and for sale. A few of the general types and forms in common use are here given. 7, shows a pair of flat-jawed tongs, the commonest shape a pair of pick-up tongs used for holding work while tem-

A, Fig. used.

B

is

pering,

and picking up pieces

C is a common shape used for holding both square and round iron, the of hot metal.

jaws

being

bent

to

stock in each case. fication of

this

shape

used for heavy steam

work. Fig. 8.

fit

A

the

modiis

also

hammer

Tongs frequently have made in some special

the jaws

shape for a particular piece of work, the object always being to have the jaws grip the work as firmly as possible. Fitting Tongs. Tongs must be always carefully fitted to the work. Tongs which take hold of the work as shown in Fig. 8. should not

FORGING The

be used.

first

pair

shown have the jaws

the second, too far apart.

When

too close together,

properly fitted the jaws should

touch the work throughout the entire length as shown in the lower sketch.

To

fit

tongs the jaws are heated red hot, the piece to be held

Fig. 10.

Fie;. 9.

placed between them, and the jaws their entire

length.

hammered down

Tongs which do not

fit

When

should never, under any circumstances, be used. all

but the smallest work, a link

is

until touching

work

the

perfectly in use

on

driven over the handles to grip the

tongs in position as shown. Set

when

Hammers and Flatters are used for smoothing off flat work The set hammer, Fig. 9, is used for working up into and narrow places. The flatter, Fig. 10, is used on wide flat surfaces. The face of the set hammer used on light work

finishing.

corners

is

about

generally

That

square.

of

lj

inches

the

flatter

about 2| inches square, although

depending upon

the sizes vary

the kind of work.

Swages, shown in Fig.

11, are

used for finishing round and con-

vex surfaces. Fig. 12.

Fig. 11.

known

The upper

as the top

tool

is

swage and

is

provided with a handle.

The

lower one is the bottom swage and is held in place by a square stem or shank which extends downward and fits into the bardie Tools of this character should never be used hole of the anvil.

on an anvil where they

them

into

place.

fit

so tight that

The swages shown

it

is

necessary to drive

here are

used

for

round

FORGING Swages are

work.

made

also

for octagonal,

hexagonal and other

shapes. Fullers, used for

made

ishing into

as

The

it

is

top fuller

is

for fin-

round corners, around bosses, and on the inside of angles

The

later on.

illustrated

when

working grooves or hollows into shape, are also

top and bottom as shown in Fig. 12.

fuller is also

used to spread metal,

wished to work the metal only in one direction.

metal spreads at right angles to the working edge of the

Swage Blocks, a common

sort of

which

is

The

fuller.

shown

in Fig.

13,

are used for a variety of purposes mostly for taking the place of

Fig. 13.

These blocks are commonly made from

bottom swages.

cast iron

and weigh about 150 pounds. Other Tools.

The

tools

used commonly are calipers, a car-

penter's two-foot steel square, dividers, a rule, shovel, tongs, ladle,

poker and a straight bar for loosening the

fire.

In addition to the

ordinary calipers, a blacksmith usually has a pair of double calipers

two dimensions may and the other for the width, of the material. When several measurements are to be made particularly on large work, a strip of light stock about |-inch by 1 similar to those

shown

in Fig. 14.

With

these,

be used, one side being set for the thickness,

inch wide

is

used.

The

with chalk or soapstone.

and used

in the

different dimensions are laid off

In use the strip

same manner

as a rule.

is

on

this

held against the work

A light

rod having a small

FORGING

10

made by bending over about \ inch of stock at right angles, sometimes used, particularly when working under the steam

bent end, is

also

hammer.

The dimensions may be

When

hooked end. iron.

The marks do

not burn

from the inside of the

laid off

hooked end

Soap-stone crayon

of the material.

on

in use the

ordinarily used for

is

off,

pulled against the end

is

marking

but will not show at a red heat.

must be made by nicking the corner Anof the bar with a chisel or by marking with the center punch. is to material hot other common way of making measurements on

Marks

to

show

at a high heat

lay off the different distances

dimensions being laid Fuel. coal,

off

The common

coke for large

on the

side of the anvil with chalk, the

from one corner or end.

fires

fuel for small fires

"soft" or bituminous

is

furnaces, and occasionally hard coal

and

The soft coal used known as smithing coal.

in small furnaces. is

of a grade

It

should be very clean and free from

impurities.

A lump

of

good forge coal

breaks easily with a crumbly looking fracture

and the coal shows clean and

bright on

up

all faces.

It will

not break

"steaming" coal

into layers as

will,

seamy looking breaks being by the more or less earthy If forge coal splits and impurites.

these

caused

shows dull looking streaks or is

poor

clinker

Good

coal.

and

breaks

used, the coal

is

watched. first

When

easily.

up

fire.

It

before

be dampening, and not used in lumps. The fire must be carefully Fires.

Fig. 14.

class condition at all

certain depth of

broken

should

JK A

it

little

dampened and kept

wet before putting on the

should be in

layers,

coal has

fire is

It is

very important that

it

times for the work in hand.

always necessary.

If

the

fire

be too

making There should be depth enough

shallow, the cold blast will penetrate the

impossible to heat the metal.

fine

fire

in spots,

it

to

FORGING For small work there should be

the fire to prevent this.

three or four inches of

11

fire

below the metal that

should also be thickness enough of

is

There

above the work being heated

fire

prevent the metal from losing heat to the outside

to

at least

heating.

The

air.

general rule the it

may be made

When

a small

tightly

around the

For

fire is

added

spread.

wanted the damp coal should be packed down

sides

and the center

up

of the fire loosened

slightly.

is packed down hard in the shape of an The block is then removed and the fire started in These mounds are left undisturbed and fresh fuel is

left.

shape of coke which has either been previously

to the fire in the

made by

loosely

partially

burning

the fuel

is

to coke, or

it

bought ready made.

is

constantly added around the sides where

This coke

into coke.

fire and With a small

banking a quantity of green coal over the

raked into the center of the

is

and more coal added around the

sides

is

turned

as

wanted

it

fire

and patted down

keep the

to

shape.

When

Oxidizing and Reducing Fires.

through the

fire all

the oxygen

which

When

just

brightly

fire

and

all

of the

Very

may even

as a reducing

air is

scale

away oxygen,

it is

Banking the Fire.

wood

it is

burned, the

iron.

it is

known

as it.

fire is in

fire

burning

good condition

This sort of a

when

the

an oxidizing

a reducing

The

This black

formed and some of the scale already

In other words,

give oxygen to anything,

Stock.

is is

blown

is

air.

possible to avoid

sort of a fire is

admitted to keep the

being

be turned back to

fire.

cing a block of

This

iron).

oxygen

little

blast

coat of oxide, or scale, (the

and should not be used when

enough

for heating.

formed

from heated

falls

an oxidizing

much

too

not burned out of the

is

attacks the iron, forming a heavy

take

bar, allowing

fire to

which green coal

the hole

scale

by a

started

side of

fire in

fire

the sides, causing the

work a small round fire is used. For heavier heating the by placing a large block on top of the tuyere, on each

light

oblong mound.

fire

wanted larger

If the fire is

by loosening the edges of the

so

come through around

the blast to

fire is

follow the blast.

fire will

fire

As a

should be kept as small as possible to heat the work properly.

fire

fire.

fire is

known

condition to

If in condition to

fire.

may be

in the center

fire is in

kept for some time by pla-

and covering over with

Material from which forgings are ordinarily

fresh coal.

made comes

FOEGING

12

shop

to the forge

in the

shape of bars having uniform sections through-

out; generally round, square, or rectangular in section,

from ^-inch thick

Bars are ordinarily 12

order.

Heavier

to 18 inches square.

20

to

and varying be had to

may

sizes

Thin

feet in length.

stuff,

an inch or less in thickness, usually comes in strips of about 40

may be had from

This

Steel also

comes

stock up to six or eight inches wide.

about

in bars generally

known

ordinary sizes of tool steel stock are price

is

fixed

on these base

than the base

Thus

steel,

?

T6

The

and the

charged for at an increase in price.

which

grades about 14 cents a pound. character,

as base sizes

Tool

Stock of a larger or smaller size

sizes.

sizes is generally

inch square tool

six or eight feet long.

f of feet.

size, is

worth in certain

Steel of exactly the

same grade and

is

a base

of an inch square, costs about 18 cents.

WELDING. or iron be

If a piece of steel

raised the metal

becomes

softer.

heated, as

the welding heat, at which the metal

temperature

the

Finally a heat

so soft that

is

similarly heated be placed in contact, they will stick.

so heated be placed together into

one

piece.

difficulty in

and

This process

welding

cleanly.

is

If the

is

reached, called

is

if

two pieces

If the pieces

and hammered, they may be joined is

known

to heat properly,

temperature

is

as welding.

The

greatest

which must be done evenly

raised too high, the iron will

temperature be

burn, throwing off bright star-like sparks.

If the

too low, the pieces will not stick to each other.

The proper heat can may be easily done by

only be determined by experimenting, which

doubling over a piece of scrap iron for two or three inches and welding into a solid piece.

When is

heating wrought iron and mild

from the

fire

with the air white it

steel,

as the welding heat

reached, small particles of the metal are melted and blown

is

stars.

upward

by the blast. As these small particles come in contact they burn and form small explosive sparks, like little Whenever these sparks are seen coming from the fire,

a sure indication that the iron

is

burning.

These sparks are

The sometimes used as a sort of an indication of the welding heat. of the appearance the heat is the by of determining only sure way heated iron, which might be described as sort of creamy white.

The

FORGING welding heat

sometimes described as a white heat.

is

correct, as iron or steel is never

may be

This

melted.

13

easily

of metal are welded together there steel is

good weld.

It is

are put together,

two pieces

must be nothing between them.

necessary

when

welding, to heat the iron or

melted scale

is

the joint or scarf

if

easily forced

is

This

a very high heat,

These are used

Fluxes. is

from between the two

it

pieces, leaving

This scale only melts

be kept free from

to-

it

would be

scale.

lower the melting point of the scale.

The metal

raised to the welding heat

is

then put back into

and the weld made as usual.

acted upon by the flux and melts at a lower heat than

is

no flux

is

at

sprinkled on the surfaces to be joined just before the

metal reaches the welding heat. fire,

the two pieces

higher than the heat at which

weld the iron could

possible. to

flux

much

when

steel to

properly made, most of this

the clean surfaces of the metal in contact.

scale

When

always covered with scale (iron oxide).

a high enough temperature to melt this scale and

the

not

when

allowed to stay on the surfaces to be joined, will prevent a

scale, if

The

is

proved by comparing a piece of wrought

iron at welding heat, with an ordinary arc lamp.

Heated iron or

This

raised to a white heat even

used.

As the

flux melts

it

The when

spreads, or runs, over the hot

metal and forms a sort of protective covering, which, by keeping out the

air,

flux in

prevents to a large extent, the formation of more scale.

no way acts as a cement or glue

but merely helps to melt

off

The

to stick the pieces together,

the scale already formed, and prevents

the formation of more.

Sand and Borax.

may

in place of is

These substances are common

fluxes.

be used when welding wrought iron and machine

sand for

a better flux as

it

fine

work and when welding

steel;

tool steel.

Sand borax

Borax

melts at a lower temperature than sand, and thus

makes welding

possible at a lower heat. Borax and salammoniac (ammonium-chloride) are sometimes mixed and used as a welding

compound, or

flux, the

proportion being about four parts borax to

one part salammoniac.

This mixture is also a good flux for brazing. Borax contains a large amount of water which makes it boil and foam when melting and in this condition is very liable to drop away from the heating metal. If borax be heated red hot and allowed to cool, the

water

is

driven off and the borax

left in

a glass like condition.

FORCING

14

Borax treated as

it

this

way and then powdered,

is

the best for welding,

melts and sticks to the metal without any boiling.

Welding Compounds are

Some of compounds are

fluxes

serving the

same purpose as

sand or borax.

the better ones use borax as a basis.

of these

first'

class for their

Some

purpose and others are

not as good, being simply intended as cheap substitutes for borax.

This is made by simply placing two or more on top of each other and welding them in a lump or slab. Scrap iron is worked up in this way by making a pile six or eight inches square and eighteen inches or two feet long on a board, such as Fagot Weld.

pieces

Fig. 15.

shown in

in Fig. 15.

This

pile

is

bound together with wires and placed

a furnace, fluxed with sand, and welded into a solid lump under a

These lumps are afterwards worked out in bars by rolling or hammering. When a large piece is wanted, two or more of these bars are placed together and welded. Scarfing. For most welding the ends of the pieces to be joined must be so shaped that when welded they will make a smooth joint. This shaping of the ends is known as scarfing, and the shaped end steam hammer. or slabs

is

The

called a scarf.

scarfed ends should not

fit

tightly before

welding, but should be so shaped that they touch in the center of the

somewhat open. In this way when the weld made, the melted scale is forced from between the pieces. If the

joint, leaving the sides is

scarfs

were made

to

touch on the edge of the

joint, leaving the center

hollow, the scale not having a chance to escape, would be held in the center of the joint, leaving a

weak

place,

and making a bad weld.

FORGING Lap Weld.

This

is

the

common weld

used for joining

flat

bars

be welded are scarfed or shaped as shown In preparing, the ends of the pieces to be welded should

The ends

together.

15

in Fig. 16.

to

Fig. 16.

be

first

bar.

upset until they are considerably thicker than the rest of the

This

and

scaling,

done

to allow for the iron that

also to allow for the

is lost

by

must work the scarfFor heavy work a fuller and

may

be done with a hand hammer.

is

For

light

After upsetting on light work, the end to be

Fig. 18.

Fig. 17.

roughly shaped with the pene end of the

trated in Fig. 17, the final finishing being the

or

this reduces the size of the iron at that point, the pieces

sledge should be used.

scarfed

off,

hammering when welding the pieces well hammered,

be upset to allow for this reduction in size. ing

burns

To make a proper weld the joint should be

together.

and as

is

hammer

done with the

flat

as illusface of

hammer. For

this

work

(finishing the

edge of the scarf) as well as

all

FORGING

16

pointed work, the end of the bar should be brought to the extreme

edge of the anvil in the manner indicated in Fig. hard blow

may

In this

18.

be struck with the center of the face of the

without danger of striking the

way a

hammer

hammer on the anvil. For all ordinary may be about 1^ times the thick-

lap welding the length of the scarf

Thus on a bar

ness of the bar

^-inch thick, the scarf will be about f of an inch long.

The width

of

the end, Fig. 16, should be slightly less

than the

width of

the

bar.

In welding the pieces together the the

first

piece held by

Fig. 19.

the helper

should be placed scarf side up on the anvil and the second piece laid on top, scarf side down, over-

As

lapping them to about the amount shown in Fig. 19. erally

somewhat

difficult to

it

gen-

is

lay the top piece directly in place,

it

should be steadied by resting lightly the corner of

against

and

the anvil

thus "steered" into place.

Round Lap Weld.

This

the

is

weld used to join round bars end to

end

to

form a continuous bar.

precautions regarding

All the

the scarf,

etc.,

used for making the lap weld should be taken with eral

this as well.

shape of the scarf

Fig. 16.

It will

is

The

gen-

shown

in

be noticed that the

hammered to a sharp point. If the scarf be made with a flat or chiselend

is

shaped end similar the sides of

cause considerable trouble, as entirely

a pointed scarf the weld

swages.

it

will

around the bar before the

two sides only.

to

the

flat

lap

weld, the corners will project beyond

Fig. 20.

This

may

is

the

bar in welding and

then be necessary to work joint

be closed down.

With

be frequently made by hammering on

not so important

when welding between

FORGING When

17

is made, the exact amount and scarfed as though making a of stock may be cut, the ends upset round lap weld, the stock bent into shape as shown in Fig. 20 and

Ring Round Stock.

a ring

The ends should be lapped sideways as shown. may be welded by simply laying it flat on

welded.

position a ring

while

if

lapped the other way, B, one end

in,

In this the anvil,

the other out,

be necessary to do the welding over the horn of the anvil.

In

it

all

would weld-

hammering may be done

the piece should be so lapped that the

in

ing the quickest and easiest manner.

In work of this character when the

Allowance for Welding. stock

due

is

cut to a certain length, allowance

on how the

exact

carefully the iron

make

to

The

to welding.

amount which*

is

The

the weld. is

is

sometimes made for

loss

amount is hard to determine, depending heated and the number of heats required

only real loss which occurs in welding

burned

off

and

Of

lost in scale.

course

is

when

preparing for the weld, the ends of the pieces are upset and the stock

The

consequently shortened.

piece

is

still

further shortened

by

when making the weld, but as" all of this material afterwards hammered back into shape no loss occurs. No rules

overlapping the ends is

can be given for the

loss in welding,

but as a rough guide on small

work, a length of stock equal to from j to f the thickness of the bar Work of this kind should will probably be about right for waste.

be watched very closely and the stock measured before and after welding in order to determine exactly how much stock is lost.

The

Chain Links. ing a chain link

a

"U"

to

first

step in

mak-

bend the stock

into

shape, care being taken to have

"U"

the

the legs of length.

is

The

even

exactly

scarf used

is

in

approximately

Fig. 21.

the pointed shape used for a round lap

weld the

scarf.

An

"U" shaped

This

is

flattened

hammer, the

easy method of scarfing piece

is

laid

on

by striking directly down with the

piece being

moved

This operation leaves a

and works

it

One end

as follows:

of

the anvil as indicated in Fig. 21. flat

slightly to the left, as

arrow, after each blow, until the end

piece

is

is

reached.

series of little steps at the

out in a more or

face of the

shown by the

less

end of the

pointed shape as shown in

FORGING Fig. 22 at A.

The

point should be finished by placing

horn of the anvil and touching up with a few scarfing the other

end of the "U"

it

over the After

light blows.

same manner the ends are B and welded

in the

overlapped as indicated at

A^>

The second

together.

spread open, and the It

The third is joined on made on a commercial

scarfed,

When

this, etc.

scale, light links

always

scarfed but sometimes

hammered

together and welded in

not

simply

one heat.

Fig. 22.

is

link inserted.

then closed up again and welded.

is

are

link

first

This

is

not possible in ordi-

nary work.

A

Band Ring. flat

ways

is

method

making a band

of

Stock

illustrated in Fig. 23.

is

ring from iron bent

cut to length, the ends

upset and scarfed, using a regular flat

weid

scarf,

and the ring bent

and welded; the welding being done over the horn of the The heating must be careanvil. into shape

done or the outside lap

fully

be burned before the

will

inside

is

Fig. 23.

nearly hot enough to weld. Flat or

Washer Ring.

iron edgeways.

The ends

This

is

made by bending

a ring

of the stock are

first

flat

upset but not scarfed,

except for careful work, the ring bent into shape, and the corners

trimmed

off

on radial

lines as

shown

The ends are then scarfed fuller or pene of a hammer

in Fiff. 24.

with a

and lapped over ready as

shown

Butt Weld. Fig. 24.

weld, of this

it is

known

welding

When

pieces are

simply welded together end to end making a square joint through the

Fig. 25.

as a butt weld.

kind to round the ends

ends are heated and driven

for

in Fig. 25.

It is

best

when making a weld

slightly as illustrated in Fig. 26.

together and

this

The

round shape forces

FOKGING out the scale and leaves a clean joint. together they are

a burr.

As the

upset at the joint,

less

pieces are driven

making a

sort of

This upset part should be worked down at a welding heat

between swages. weld.

more or

19

Long

A

pieces

butt weld

may

not as safe or as strong as a lap

is

be butt welded in the

fire.

This

is

done

Fig. 26.

by placing one piece

in the

fire,

from each side of the

forge.

When

is reached the pieces are placed end to end, one up" with a heavy weight, and the weld made by striking with a sledge hammer against the end of the other piece. Jump Weld. Another form of butt weld shown in Fig. 27 is a jump weld which however is a form which should be avoided as much as possible, as it is very liable to be weak. In making a weld

the welding heat

piece "backed

Fig. 27.

Fig. 28.

of this kind the piece to be butted on the other should have

upset in such a

manner

wider the better.

as to flare out

When the

weld

is

down with a fuller or set hammer, Split Weld for Thin Stock. difficult to join

and form

made,

its

end

sort of a flange, the

this flange

may

be worked

thus making a fairly strong weld.

Very thin stock

is

sometimes

with the ordinary lap weld for the reason that the

FORGING

20

pieces

lose their heat so rapidly that

them together on the This

heat.

as

shown

down

difficulty is

in Fig. 28.

have cooled below the welding

somewhat overcome by shaping the ends are tapered to a blunt edge and split an inch or so, depending upon the thickness

The ends

the center for half

of the stock.

almost impossible to get

is

it

anvil before they

Half of each

split

edge

bent up, the other down, the

is

pieces are driven tightly together

the split parts closed

shown

other as is

down on each The joint

in Fig. 28.

then heated and welded.

weld

and

This

is

a

sometimes used for welding

spring

or tool

steel,

or

Cleft

Split

Heavy

Stock.

steel.

Weld

stock

Heavy

for

is

sometimes

welded by using a scarf of the shape

shown in Fig. 29. One piece is split and shaped into a "Y" while the other has

end brought

its

When

to a blunt

point.

properly shaped, the pieces are

heated to the welding heat and driven together.

then closed

The ends of the "Y" are down over the other piece

A

and the weld completed. heat

is

sometimes taken

This weld

is

tool

to

steel

second

do

when

often used iron

to

this.

joining

machine

or

steel.

Sometimes the pieces are placed Fig. 29.

Angle Weld.

In

all

should be remembered that the object of the scarfing the pieces to be welded that

smooth

joint

eral equally

and

it

made.

made

they will

when properly hammered. good methods of scarfing

fit

together

Fig. 30

of

flat

way

in

for the

Both

welding to so

it

shape

and form

a

same

sort of a weld,

given

here

is

not

which that particular weld may be

shows one way of scarfing

iron.

is

Frequently there are sev-

should be remembered that the method

necessarily the only

to-

gether before taking the welding heat.

pieces

are

for a right

scarfed

angled weld

exactly alike,

the

_

FORGING scarfing being

21

done by the pene end of the hammer.

may be

the ends of the pieces

If necessary,

Care should

upset before scarfing.

Fig. 31.

Fie. 30.

be used here as in other welds to see that the pieces touch center of the scarf, otherwise a pocket will be retain the scale

A

T=Weld.

in the will

spoil the weld.

method

The stem

Fig. 31. in

and

first

formed which

A

of scarfing for a

T-weld

is

illustrated in

should be placed on the bar B, when welding,

about the position shown by the dotted

line.

T=Weld Round Stock. Two methods of scarfing for a T-weld made from round stock are shown in Fig. 32. The scarfs are formed mostly with the pene end of the hammer. The illustration will explain itself. The stock should be well upset in either method. Welding Tool Steel. The general method of scarfing is the same in all welding but greater care must be used in heating when welding tool steel. The flux used for welding tool steel should be the steel

salammoniac and borax mixture mentioned before. or low carbon steel

To weld

may

be satisfactorily welded

steel successfully the following precautions

and

if

care

Spring is

used.

should be ob-

Put sufficient coal add more coal while taking the welding heat. Upset both pieces near the end and scarf When possible, punch a hole and rivet the two pieces carefully. Heat the steel to a full red heat and sprinkle with borax. together. Replace in the fire and raise to the welding heat. Clean the scarfed Clean the

served.

upon the

surface

fire

and

appearance

fire

so that

it

of all cinders

strike lightly at

of steel

when

ashes.

be unnecessary

will

first,

at a

to

followed by heavier blows.

welding heat

is

The

a pale straw color.

FORGING

22

Always avoid a weld of high carbon Steel

may

be welded

also

manufacturing of edged

which a piece of

steel is

tools.

welded

alone,

steel

wrought

to

when

This

iron.

The. body of the tool to

is

work

is

best

in the

of iron, to

form the cutting edge. of

possible.

done

is

This

class

done with a

fire

anthracite coal, though coke,

of

may

or charcoal

be used.

The

should be burning brightly

fire

when

the heating

done.

is

Lay

the iron and steel on the coal un-

they

are

red

sprinkle

the

surfaces

til

with the flux and

A

Fig. 32.

A

convenient method of

doing

will

is

to a straw color lay

to

do the work.

Be

let

have the powdered

As soon as the heat has them together and strike.

blow of a drop hammer, or four or

single

both

vitrify.

(borax preferred) in a pepper pot.

changed the metals

of it

this

flux

Then

hot.

five

with a light sledge

sure that these pieces are well covered with a

flux before attempting to weld.

CALCULATION OF STOCK FOR BENT SHAPES. It is

always convenient and frequently necessary to know the exact

amount of stock required to make a given

piece of work.

There are four

^01

8"

ÂŁ

Fig 33.

Fie. 34.

general methods used for determining

method,

if it

this.

can be used conveniently,

Taking as an example the bent piece

is

The first and most accurate mathematical calculation.

illustrated in Fig. 33.

If the out-

FORGING

23

sideofthisbe measured, it would seem as though 16 inches of stock were

amount.

er

be measured, 14 inches would seem the prop-

If the inside

required.

has been found by experiment that

It

a piece of

if

this piece of

drawn on it through the, center, and stock then be. bent and the lengths of the inside, center,

and outside

lines

straight stock

siderably

betaken and a

be measured, the outside

the

as

piece

center line

of stock required for

by measuring the center measured, 1\ inches

is

if

be the length for each

will

make

On

circles

and parts of

The

//V

=]

|

\^----|

J

^

\

1

s

•

1

"

~*-

to

)\

\'^

r

more

accurately,

bend up the ring

stock

the

the center line,

or,

illustration, the stock

diameter of the ring

J

may

circles the length of stock

circle,

is

one

3.

1416.

necessary

in Fig. 34,

would

The

inside

be calculated as follows

I

Fig_ 35.

made by

when meas-

line.

found by multiplying the diameter

by 3} As an

JTx

7X

\ '\Jv^l

|_-

that particular bend.

circumference, or distance around a is

y^~~l

return to

making a

thus

leg,

a universal rule which should always be followed

be easily calculated.

t

To

the center line of the stock be

uring stock, to take the length of the center Circles.

shorten

comparatively

curve or bend.

line of the

total of 15 inches of stock required to

This

remain

will

universally true,

is

In this case,

example:

lengthen con-

line will

inside line will

and the proper length making any bent shape may always be obtained This

unaltered in length.

first

The

bent.

is

correspondingly, while the

the

line

is

:

and

six inches

inch

thick.

This

would make the diameter of the circle shown by C, which may be called the Cal-

culating Diameter, seven inches,

and the length of stock required

would be 7X3-}- or 22 inches. Link.

A

in Fig. 35.

combination of

This link

may

circle

and

straight lires

end, with two straight pieces at the sides. of the ends being

inches long. inches.

The

two inches, would

The or

The

outside diameter

two

would be 1^

then required for the ends would

approximately 4-f^ inches.

straight sides will take

illustrated

leave the straight sides each

calculating diameter for the ends

total length of stock

bel|X3}=4f

is

be divided into two semicircles at the

two inches of stock, the

As each of the

total length required

FOEGING

24

would be 4" + 4-^-"=8f| inches With a slight allowance for welding, the amount cut should be 8f ". Another method of measuring stock

is

by using a measuring wheel such as This

is

is

shown

in Fig. 36.

simply a light running wheel mounted on

a handle with some sort of a pointer attacked.

The wheel

is

sometimes made with a circum-

ference of 24 inches

lightly in contact

and the rim graduated

To

inches and eights.

use

the wheel

it,

is

in

placed

with the line or object which

it

wished to measure, with the zero mark on the wheel corresponding to the point from which

is

is started. The wheel is then pushed along the surface following the line to be measured, with just enough pressure to cause

the measurement

it

Fig. 36.

By

to revolve.

counting the revolutions and

parts of a revolution

quired distance Scrolls

methods. size

may

made by

the wheel, the re-

be easily measured.

and Irregular Shapes may be measured by

The commoner way

is

to lay the scroll or

and measure the length by laying on

either of

shape

this full sized

two

off full

drawing a

string or thin piece of wire, causing the string or wire to follow the

center line of the bent stock.

The

wire or string

is

then straightened

and the length measured. This is about the easiest and best way of measuring work of this character. Another method which is more practical in the drafting room, consists of using a pair of dividers.

The

points of the dividers are set fairly close together

line is

then stepped

number

off

and the number of

and the center

steps counted.

of spaces are then laid off along a straight line

The same

and the length

measured.

FORGING OPERATIONS. Shaping.

hammer. bending. diameter.

After the metal has been heated

This shaping

may

consist

In drawing a bar of iron Upsetting

it is

shaped with the

drawing,

made

upsetting

hammer;

This work

or

longer and of a smaller

consists of shortening the bar with

sponding increase of diameter. helper using a sledge

it is

of

is

a corre-

usually done with a

the smith using a light

hand hammer.

FORGING They

strike alternate blows.

which the smith

and

strikes

The

25

helper must watch the point upon

strike in the

same

the anvil' by the smith

A

man.

blow on

a signal to stop striking.

As the hammer usually marks the metal, it metal a little full and finish by the use

Finishing.

customary

is

Where two

place.

helpers are employed the smith strikes after each

to leave the

flatters

and swages.

applies

to

work

been shaped sledge.

is

of

This

that

has

under

the

Light work can be

dressed smoothly, and the

hammer can be made to literate its own marks. Drawing Out.

Fig. 37. i

other forging operations where heavy best to heat the

without injury.

work

to as high a

work

out

n g

to

is

When

a piece of work

out and spreads nearly as it

out longer and wider.

longer, all

the

in increasing

the stock

is

hammering

it is

hammered od

always

will

much

face, the reason

the anvil face

stand

faster

it

by

being

flattens

much in width

as

As the piece

not wanted wider but merely

is

it

does in length, working

work spent

the width of

wasted. is

is

as well as in all

be done,

be drawn out

working over the horn of the anvil than on the this:

In draw-

temperature as the metal

Work can sometimes

ob-

—£-

If the

done over the

horn of the anvil as

illus-

Fig. 38.

trated in Fig. 37, the round-

ed horn acts as a blunt wedge, forcing the metal lengthwise and thus utilizes

almost the entire energy of a blow in stretching

in the desired direction.

the metal

Fullers are also used to serve

purpose and when working under the steam

hammer

the

same

a round bar

sometimes takes the place of the

fuller or horn of the anvil. Drawing Out and Pointing Round Stock. When drawing out or pointing round stock, it should always first be forged down square to the required size and then in as few blows as possible, rounded up.

Fig. 38 illustrates, in a general way, the different steps in

drawing

FORGING

26

down a round bar from a large to a smaller size, the first step being to hammer it down square as at B. This square shape is then made octagonal as at

C and

an attempt be made

the octagon

to

hammer

finally

is

rounded up as

the bar by pounding

it

D.

at

If

round and

round without the preliminary squaring, the bar to split

is

very liable

through the center, the

action being a good deal as

il-

lustrated in Fig. 39, the effect

of the

Fig. 40.

blow coming as shown

The metal

by the arrows A. is

squeezed together in

this direction

rection at right angles as indicated

piece

be

the bar,

if it

by the arrows B.

for another

slightly rolled

each other, and cracks and

and forced apart

splits will

in

the di-

Then

blow, the sides will

if

the

roll

by

sooner or later develop, leaving

should be sawed through the center, in a good deal the

shape shown in Fig. 40. conical points as

it is

Particular care should be taken in

making

down to

a round

almost impossible to work stock

point unless the point be

first

forged

down

to a

square or pyramidal

shape.

ÂŁL

Fie. 42.

Fig. 41.

Truing

Up Work.

In drawing out

it

often

happens that the

bar becomes worked into an irregular or diamond shape, similar to the section

bad

shown

To remedy

in Fig. 41.

this,

and square up the

corners, the bar should be laid across the anvil

much

as

shown

by the arrow.

in Fig. 42, the

Just as the

hammer

strikes the

given a sort of sliding motion.

No

up a corner by

down upon

striking squarely

be done

ing should

all

the bar and

away from

in

and worked

blows coming in the direction indicated

work

it

should be

made to square work. The hammer-

attempt should be the

such a way as to force the metal back into

the high corner.

FORGING Upsetting.

length

When

a piece

27

worked

is

shortened and either or both

is

creased, the piece

is

such a way that

in

and the operation

said to be upset

its

thickness and width in-

its

known

is

as

There are several methods of upsetting, the one used

upsetting.

depending largely upon the shape of the work.

work

In short pieces the

on end

generally stood

is

hammering being done directly down upon the The work should upper end. always be kept straight, and as soon as a bend or kink is started, on the

anvil, the

be

should

it

When

straightened out.

a long piece

it

and Fig. 43.

is

generally

forth

horizontally

end against the of the blow has a decided influence upon

blows

shown by the sketches

affect

be up-

swung back and the upsetting done by ramming the

set

piece, as

to

is

the metal

of the

for a short

two

The

anvil.

the shape of

the upset

rivets in Fig. 43.

distance only, as

swelled out end, while the effect of heavier blows

effect

Light

shown by the

is felt

jnore uni-

formly throughout the entire length.

When

rivets are to

be driven

be heavy, thus upsetting the is

wanted

move, as

to

to

fill

holes tightly, the blows should

rivet tightly into the holes.

hold two pieces together in such a

way

If a rivet

that they

may

for instance the rivet

in a pair of

tongs, the

head

should be formed with light blows, thus working only the

end of the of the

rivet.

work which

part which will

The is

Fig. 44.

part

heated

to

the

highest

temperature

be most upset, and when upsetting

one point only, that point should be heated

to the highest

leaving the other parts of the bar as cold as possible. pieces

is

is

as upsetting plates.

set in the floor.

These

the

temperature,

Upsetting long

sometimes done by raising the piece and allowing

on a heavy cast-iron plate

is

wished at

it

plates are

to

drop

known

FORGING Two

Punching.

kinds of punches

commonly used for hand punch used with a are

making holes in hot metal; the straight hand hammer and the one used for heavier stock, provided with a handle and used with a sledge hammer. Punches should of course be made of tool steel. For punching small holes

hand punch

iron a ily

used.

This

thin

ordinar-

is

a bar of

is

round or octagonal

in

steel,

eight

or ten inches in length, with

the end forged •p io

.

45

ly smaller

punched.

Such a punch

for

round holes

is

down

tapering

same shape, but

to the

slight-

than the hole to be

shown

in Fig. 44.

The

end of the punch should be perfectly square across, not at all rounding. For heavier and faster work with a helper, a punch similar to

Fig. 45

is

used, the striking being done with a sledge

Fig. 46 illustrates the successive steps in

through a piece of hot

and the punch driven

hammer.

punching a clean hole

The work is first laid flat on the anvil about half way through as shown at A. This iron.

compresses the metal directly underneath the end of the punch and

Fig. 46.

raises a slight bulge

The

on the opposite side of the bar.

piece

is

then turned over and the punch driven into the bar from this side (the hole being located

by the bulge) while the bar

is

lying flat

on

leaving the

The punch should be driven about half of the way through, work as at C. The bar is then moved over the small

round hole

in the

the anvil.

end of the

anvil, or is placed

on some object having

a hole slightly larger than the hole to be punched, and the punch

FORGING

29

driven clear through, driving out the small piece

A

and leaving the

punch comwork from one side. If this were done, however, the hole would be left as shown at E, one side would be rounded in, and the other side would be bulged out, while the hole would have

hole as

shown

at

D.

would seem

It

easier to drive the

pletely through the

a decided taper, being larger

end from which the punching

at the

was done. If the piece be thick, after the hole is started, a little powdered coal is put in and the punching continued. The coal prevents the punch from sticking to some extent. Ring and Eye Bending. In

making a step

ring

five inches in

should be heated for about half

extreme end of the piece of the anvil

is first

its

length.

required.

In

four or

rings

diameter, the stock

The bar is The blows

illustrated in Fig. 47.

down

as

it is

fed forward. fall

outside of the point

hammer

This bends the iron and does not

One-half of the

out of shape.

first

In starting the bend, the

should not come directly on top of the horn but

it

the

bent by placing the bar across the horn

and bending it down as

then pushed ahead and bent

of support as illustrated.

or eye

of course, to calculate the

amount of stock making ordinary

Fig. 48.

Fig. 47.

is

circle is

bent in this way, the stock

^c 2nd.

/**

^>

4

th.

Fig. 49.

turned end for end, the other end heated, and the second half bent in the

same way

as the

first,

the bending being started from

the

end as before.

Eye bending it

is

done

in

a somewhat d'fTerent manner.

be required to bend up an eye as shown in Fig. 48.

the

amount

of stock required:

The diameter

To

Suppose calculate

in this case to

be used

FOEGING

30

two inches, and the amount of stock required 2 X3}" = 6f", or practically 6f". This distance is laid off by making a chalk mark on the anvil 6f " from the end. The iron is heated and placed against is

//

the anvil with one end on the chalk

mark and the other end extendThe hand hammer is then held on the

ing over the end of the anvil.

bar with one edge at the edge of the anvil, thus measuring off the required distance on the bar. Still holding the hammer on the

bar the piece

is

the edge of the of the anvil

laid across the anvil, with

hammer even

the edge or corner.

down Fig. 50.

that

all

the bending

is

with the edge

and the 6f inches extending over This piece

into a right angle as

is

shown

then bent in the first

illustration of Fig. 49.

The

much

as the ring, except

the

same manner

eye

is

bent in

done from one end, the successive steps Small eyes are closed up in the

being shown in the illustration.

manner shown in Fig. 50. Bend with Square Forged Corner.

Brackets and other forg-

s A

---.

Fig. 51.

ings are frequently as

shown

the

first

made with

at C, Fig. 51.

This

method the corner

is

the outside corner square and sharp,

may

be done in either of two ways; by

bent from the size of stock required

for the sides, being first bent to the

shape of A.

This corner

is

then

FORGING

31

squared by upsetting the metal at the bend, the blows coming as shown by the arrows at B. The work should rest on the anvil face, and not over one corner, while being hammered. The second method is to use thicker stock and draw out the ends leaving a hump, shown at D, where the outside corner of the

jsL.

r/f"

£

IE '*/

£±-

-Fv

*r

-*h-

Fig. 52.

bend

is

come.

to

The

dotted lines

show the

original shape of the

bar; the solid lines the shape before bending.

taken of the size used in the in place of

The

first

Sometimes stock

method and upset

to

form the

is

ridge,

drawing out the heavier stock.

first

method

is

the one

more commonly used on medium

sized work.

SIMPLE FORGING. Twisted Gate Hook.

It

should be understood that the descrip-

tion given here will serve not only as a description of the particular

piece in question but also as a general description of a variety of

y

i

G D

Fig. 53.

similarly shaped forgings.

Fig. 54.

The methods used may be employed

on other forgings of the same general shape. Fig. 52 to

To

shows a twisted gate hook.

start with,

it

is

necessary

determine exactly what lengths the different parts of the hook

have

to shape.

Before bending, the work

is

will

and before they are bent first drawn down to size as

after they are forged to dimensions,

FOKGING

32

is

The bar

indicated.

part,

and each end

is

hook and eye ends. \"

round required

to

is

left

drawn

square in the center

The length of make the eye,

for

round

to one-quarter inch

form the drawn out to

stock after being

Allowing about

2| inches.

is

the central to

one-quarter of an inch for the straight part before the eye

amount of stock required amount of stock for the hook it

would make the

To

obtain the

the

hook

total

full size.

If the

drawing be

is

not, a

if

reached

for the eye 2f inches.

full sized

be done directly on the drawing, but

is

necessary to lay off the measuring

may

rough sketch having

the proper dimensions should be laid off and the measuring done on that, the

measuring of course being done along the dotted center

This measuring

line.

is

done by simply laying a

line, then straightening out the string

way

this first

step

it

will

be found that 2| inches

is

on the dotted

string

and measuring

its

In

length.

required by the hook.

The

then to forge the work into the shape shown in Fig. 52.

is

The

Forming Shoulders.

shoulder

where the round stock joins the square should be forged in the manner indicated

The bar

in Fig. 53.

anvil with the point is

is

laid across the

where the shoulder

wished, lying directly on the corner of

hammer is then placed on top of the work in such a way that the p io g 5 edge of the set hammer comes directly in line with the edge of the anvil. The set hammer is then driven into the work with a sledge hammer. The bar should be turned continuthe anvil.

The

set

.

ally or

an uneven shoulder

wanted on one

worked '

flat

will

side only, as

in as indicated there.

on the anvil face while the

be the

illustrated

That set

is,

result.

in

If

Fig. 54,

a

shoulder

it

one side of the iron should

hammer works down

is

should be lie

the metal next

to the shoulder.

After the two ends of the hook are drawn out, the eye and the hook are bent up into shape. The twist in the center of the hook may be made by using either two pairs of tongs or twisting in a vise. By the latter method a mark is first made on the vise in such a way that when the end of the hook is placed even with the mark, the edge of the vise will

come

at the

end of the point where the twist

is

wanted.

FORGING The hook should be

33

heated and placed in the

between the tongs and the vise

The

twist

made by simply

is

is

vise, the

way

being grasped by a pair of tongs in such a

other end

that the distance

just equal in length to the twist.

revolving the tongs around.

In mak-

ing a twist of this kind, no al-

made

in

practically has

no

lowance need be length, as effect

it

on the length of the

stock.

A

Eye Bolts are made by two general methods, being either solid

SÂŁ

or welded.

eye bolt

A

I Fig. 56.

side of a flat bar

end

is

is

of.

solid

forged

bolt, or

sometimes

called,

started in the general

manner

illustrated in Fig. 55.

A

is

is

any punching

rounded up over the horn

is

The

the stronger.

may be nick

by using top and bottom

circle as possible before

the eye

it

made on either The

fullers as illustrated.

then rounded up as shown in Fig. 56.

should be given to seeing that the eye

much

eye

solid

eye, as

B

is.

Particular attention

forged as nearly to a perfect is

done.

the anvil,

The

stock around

by swinging

it

back

and forth as

it is hammered. when first punched is like B, but when finished should be like C. The other end of the bar is then drawn down to form

The

hole

the round shank.

shank

is

If a very long

wanted a short stub Fig. 57.

shank may

be

and a

formed

round bar of the proper

size

welded on.

Welded eye bolts may be made in two different ways. The easier method produces an eye shaped as in Fig. 57. To make such a bolt, first

scarf the

end so that

dotted line a b.

it

will

fit

over the bend of the rod along- the

Bend the eye over the horn of the anvil.

Finally bring to

a welding heat and weld in accordance with instructions already given.

FORGING

34

An lows

eye of better appearance, as shown in Fig. 58,

Upset the body of the metal as a seat

:

is

made

as fol-

for the scarf at the end,

Fig. 58.

shown

Scarf the end of the bar and bend over the horn

at a, Fig. 58.

of the anvil into a true circle to

fit

the seat at

a,

and then weld

as

before.

The

length of metal required for an eye or ring

to the length of the

is

nearly equal

circumference of a circle whose diameter to the

mean diameter

equal

is

Thus

of the ring.

in

Fig. 58 the length required for the eye will

be

ab

c b

approximately the length of the

circle

whose diameter is a c. Chain Hooks. These are made in a of shapes and with solid or welded ety the general

method

varieyes,

making the eyes being "Eye Bolts". shown in Fig. 59. The

of

exactly as described before under

A common

Fig. 59.

stock

To

is

shape

is

forged into shape similar to Fig. 60

A

the drawing

is

meas-

ured in the same way as described in making the gate hook.

The

before being bent.

weakest point a; re

in

in Fig. 59.

determine the length

most hooks

is

the part lying between the lines

marked

This part of the

hook should be heavier and stronger than the other parts. is

When

put on the hook, there

is

a strain

always Fie. 60.

a tendency to straighten out or

to

assume the shape shown by the dotted

hook

into shape, the

dimension B, Fig. 60,

the heaviest part of the

hook

is

lines.

hook comes

entirely forged to size,

it

in this

When

forging the

should be made such

weakest point.

that

After the

should be bent into shape.

Hooks

FORGING made from round and square

are also

35

When made

iron.

for

ing over a link, and so shaped that the throat or opening large link

enough

to slip

which, of course, angles, the

hook

easily over a

narrow

down

to the

to

one

turned at right

is is

just

too

edgewise, but

slip off of this link

hook-

is

known

as a grab

hook.

A

Hoisting Hooks.

widely ac-

cepted shape for hooks of acter used

shown on

is

The shape and formulae

Fig. 61. for the

on cranes

this char-

dimensions are given by Mr.

Henry R. Town in his "Treatise on Cranes". T= Working load in tons A = Diameter of of 2,000 lbs.

Fig. 61.

round stock, in inches, used the hook.

The

ticular load

is

is

size of stock required for

be used

in

_

The

line,

form

load for which the hook

is

designed

the lower line gives the size of the stock to

making the hook.

T— ^A — mulae,

The

given below.

given in the upper

to

a hook to carry any par-

llli

1

9

Q

4

5

6

8

11 1

13 X

13

2 w

24"4

2+

21-

1

_5_

11

3

11

8

T"6

4

J-TB"

4

S

14

-J

10 8

3i

other dimensions of the hook are found by the following for-

all

of the dimensions being given in inches.

D =

.5

T +

1.25

"

1

:

FOKGING

3G

f-J

showing the

will

The dimensions

be used.

size of stock to

of the

hook

be found as follows .

D =

.5

Xi+

E =

.64

X

1.33

A =

I

=

I

+

= =

1.25" 1.6"

1.33

X

If".

If' about.

1

Etc.

.915 or about

l"6

f §-".

When reducing the decimals the dimensions which have to do only with the bending of the hook, point, etc.,

may

i.e.,

the opening, length, the length of

be taken to the nearest 16th, but the dimensions

through the body of the hook or stock should be reduced to the nearest

32nd on small hooks.

in question,

500

lbs.

The completed dimensions

capacity,

D =

would be as

= J = k= L =

E = If" -U 5// f =: H* T6 1 3//

1

G = O = Q= H

1"

I 4 1

1

13// 21// 3 2 2

11" 32

u=

3" 4

3.//

32

M=

3//

hook

2 9// 3 2

I

If"

of the

follows:

_9_// 1 6

3//

4

made by two methods, the head being made The first method is more common on small bolts and machine made bolts. The welded head is more commonly used for heavy, hand forged bolts. The upset head is Bolts.

Bolts are

by either upsetting or welding.

the stronger provided both are equally well

The

made.

always

given

size of

the

as

diameter

length of shank or stem.

known

as

ÂĽX

would mean a in diameter i.

the bolt

Thus a

is

and bolt

6", or \" bolt 6" long,

having a shank \" 6" long from the

bolt

and

under side of the head

to the

end of

the stem, having the dimensions of the 62.

bolt

shown in Fig. 62. The dimensame for the same sized bolt

sions of the bolt heads are always the

;

and are determined from the diameter of the shank. The diameter of the head, shown at D, Fig. 62, is the distance across the head from flat side to flat side, and is known as the diameter across the flats.

FORGING The

thickness of the head

diameter of the

is

taken, as

shank of the

bolt, the

37

shown

T.

at

If

S equals the

dimensions of the head would

be as follows:

D = 14 X T=S

+

S

1"

For a two-inch bolt the dimensions would be as follows: Diameter of head

The or 2".

UX

+

2"

=

\"

3|"

thickness of head would be equal to diameter of the shank,

These dimensions are

Each

rough or unfinished heads.

for

dimension of a finished head

T\

is

of

an inch

less

than the same

Fig. 63.

Bolts generally have the top corners

dimension of a rough head.

off. This may be done with a hand hammer; or a cupping tool, which is simply a set hammer with the bottom face hollowed out into a cup shape, may be used. Upset Head Bolts. The general method of making bolts of The method this kind, when a single bolt is wanted, is described below.

of the

head rounded or chamfered

of upsetting

Where

is

shown

in Fig. 64.

large quantities of bolts are to be

made, the bars are

heated in a furnace and headed by special machinery.

work

J

1

done by hand the

simplest character.

Where

tools are of

The header

consists of

correspond to the diameter of the

handle 12 or 15 inches to the disc.

The

63.

Such a

in length

tool

is

shown

should be about

hole

bolt.

larger than

a bolt with this tool

:

the nominal

A

welded

is

in

Fig.

1 g-

Fig. 64.

make

the the

a disc in which a hole has been drilled to

"H-n.

/

is

^ inch

size of iron.

To

First cut off the iron to the required length;

then heat the end to be headed, to a dull straw color; strike the end with a

hammer or against the

for the formation of the

anvil

head

and upset

it

will not pass

so that the portion intended

through the header.

place the hole of the header over the square hole in the

tail

Then of the

FORGING

38

and drop the cold end

anvil

jecting portion of the bar

of head

is

obtained.

This

of the bolt through

and upset will

it

Strike the pro-

it.

until the requisite thickness

probably leave a head of curved but

Remove

irregular outline.

from the header and square the head thus upset, on the

This

face of the anvil.

will

probably thicken the head.

Again drop the cold end through strike the

reduced

head to

and

header

the

until

proper

it

is

thick-

Fig. 65.

ness.

square the edges on the face of the anvi

smith will hold the header in his itated

if

left

a helper assists with a sledge

hand,

After which, again

In doing

this

The work

work, the

will

be

facil-

hammer.

There are a number of simple

tools in use for

clamping the

Fig. 66.

bar while

it is

being headed so as to avoid the preliminary upsetting.

Welded Head Bo3ts are made by welding a ring of square

iron

FORGING around the end of the shank

39

The

form the head.

to

ring

is

generally

bent up on the end of a bar as shown at A, Fig. 65, but not welded.

This ring

and placed on the end of the shank be left slightly open

cut off

is

The

B.

joint in the ring should

The

the expansion in welding.

shank by striking

The

bolt

is

shown

it

against the shank.

heated to the welding heat, and the

fire,

head welded up intothe quired shape.

as

Fig. 67.

it is

make

much

better chance of doing

must be used

to

sound work by welding the head

No

attention need be

paid to the joint in the ring as this will take care of siderable care

first,

way

difficult in this

a sound joint, there be-

hexagonal as required.

directly square or

re-

The ring should

not be welded round at

ing a

at

fastened to the end of the

on one side and squeezing

it

put into the

is

ring

as

to allow for

itself.

Con-

in taking the welding heat, as all the

heat which reaches the joint must pass through the ring and there is

a good chance of burning the ring before the shank reaches the

welding heat

be

lar

to

stock

The

not done slowly and carefully.

jawed tongs, such as are used

for hold-

may

be

Stock should of

three-quarters

inch square.

is

flat

about three-quarters of an inch thick,

to

as follows:

about

make

the heating

work up

ing light

made

if

Common

Tongs.

first

step

an to

is

a bend near the end simi-

A is

in Fig. 66.

The bent

then laid across the an-

in the position shown at C and the eye formed by striking down upon it with a sledge hammer. A set hammer may vil

be used for

Fig. 68.

work by placing the work flat

side down on the top of down the stock for the eye, next to the shoulder, hammer. To make the handle, enough stock may be taken

this

the anvil and working

with the set

and drawn out as shown

at

D

and a complete handle forged

way, or a small amount of stock out.

Enough round

stock

is

may be

in this

taken and a short stub forged

then welded on to

make the proper

length

FOKGING

40

shown

of handle, as

E.

The

The jaw is tapered down as shown at punch the hole for the rivet. It is always a good

in Fig. 67.

last step is to

plan to slightly crease the inside face of the jaw with a sures the jaws gripping the

ing

it

work

fuller, as this in-

firmly with the edges,

and not touchsimply at one point in the center, as they sometimes do if this crease

is

The

not made.

tongs are then riveted together, the riveting being

done with the round end of the

way

ting the

much where

it

is

in this

formed on

the rivet without upset-

Fig. 69.

very

hammer;

a head

passes through the hole.

shank of the

rivet

After riveting, the tongs

will probably be stiff or hard to move. They may be loosened up by heating the eye part red hot and moving the handles forward and backward two or three times. They should then be firmly fitted to the work to be handled. Tongs for Round Stock may be made by the general method

described above, the only difference being that after the jaws are

shaped, and before riveting together, they should be rounded up as illustrated in Fig. 68, using a fuller

Light

Tongs

trated in Fig. 69.

may

A

and swage

be made from

cut

is

made

A_

flat

as

shown.

stock in the

manner

illus-

in a piece of flat stock, with a fuller,

V

^^ Fig. 70.

near one end.

Another cut

This end

is

made on

is

twisted over at

out as indicated by the dotted in the usual light

way.

work and are

Tongs easily

right,

angles as

shown at B. drawn

the opposite side, as at C, and the end lines.

The

of this character

made.

tongs are then finished

may be

used for very

FORGING Pick=Up Tongs are made

in

much

41

the

same way

as described

above, the different steps being illustrated in Fig. 70. Bolt Tongs may be made from round stock, although square may be sometimes used to advantage. The first step is to bend the bar in the shape shown in Fig. 71. This may be done by the fuller

shown

at the edge of the anvil,

at

A, or on a swage block as at B.

The jaw

proper

ished with a

shown

is

rounded and

fuller

and swage

fin-

The

in Fig. 72.

part

as

be-

tween the jaw proper and the eye

may

be worked down into shape by

and set hammer. The may be done as indicated in Fig. 73. The eye and handle are then flattened down and drawn out, the fuller finishing

the tongs are punched, riveted together,

finished,

and

in

fitted

the

usual manner. '

Ladles similar to the one shown

in Fig.

may be made from two

74,

pieces welded together, one forming

the

or as sometimes

is

of flat stock

first

is

done, the handle "laid

handle,

may

the

other

the

A

be riveted on.

out" as shown in Fig. 75.

bowl, piece

This

A

is

B Fig. 73.

Fig. 72.

then cut out with a cold chisel and the handle welded on at the projecting point.

The bowl

heat and placing

it

is

formed by heating the stock

to

an even

over a round hole in a swage block or other object.

FOKGING

42

This hole should be

than the outside diameter of

slightly smaller

To round

the piece to be worked.

the bowl

worked

it is

in Fig. 76, with the

hammer.

the

should be done as

as indicated

pene end of

The much

forming: as possi-

by working near the edge

ble

of

the piece rather than in the cen-

properly shaped the edges should

Fie. 74.

be ground

formed as shown

which the

lip is

the bowl has been

After

ter.

in Fig. 77.

made

This

off

smooth and the

lips

done by placing the part from

is

against one of the small grooves in the side of

the swage block and driving in a piece of

small round iron, thus hollowing out the

The

stock draws in

ing rounded up.

3^

For the bowl of a

in diameter, the stock

have an outside

lip.

somewhat when be-

when

diameter

flat

about

of

ladle

should four

and be one-eighth of an inch thick. Machine steel should be used for making the bowl. If ordinary wrought iron is used inches,

the metal

is

almost sure to

Fig. 75.

split.

CALCULATION OF STOCK FOR FORGED WORK. The

calculations

was simply bent

made

remaining unaltered. shape of the stock to

know

this

previously for stock, were for stock which

into shape, the original section or size of the stock

is

There

is

a large variety of work where the

considerably changed, and where

it is

essential

amount required to make a given forging. In doing work one rule must be remembered, i.e., that the volume

the

kind of

of the stock remains unaltered although

its

shape

may

be changed.

Take as an example the forging shown in Fig. 78, let us determine the amount of stock required to make the piece. The forging is made in the general manner shown in Fig. 79.

A piece

of stock should be taken large enough in section to

block B, which will inch thick.

mean

The metal

is

that

it

will

make

the

be one inch wide and half an

worked by making the

fuller cuts as

shown

FOEGING in Fig. 79

43

and then drawing down the ends

know

being, of course, necessary to

the

to the required size,

amount

it

of stock required for

each end.

For convenience

be divided into

in calculating, the forging will

three parts, the rounded end A, the central rectangular block B,

The

the square end C.

stock used being 1"

X

i" the block

of course require just

two inches of

The end C would have

a volume of

X

=

3"

volume

The

f of a cubic inch. of, \"

X

1"

X

I",

=

inch for each inch of length.

end inches long and tiply the

짜

by the length This

volume of

A

a round shaft

2"

stock has a

\ of a cubic

The number end

C

\\ inches.

The

or

four

cylinder

of the

A

give the

ill

X

a:

X

4

o-tf

[} and the amount of

stock required piece

\ or

stock.

square of the radius (h the diameter) by 3y and then multiply

cylinder.

to

would be \\

There

is

-r-

will

To find the volume of a cylinder, mul-

in diameter.

this result

X 4=

A

be. f

and

YX

of inches of stock required for the

would then

B

is,

of course,

make -r-

\

some

Fig. 78.

this

=

Ij-,

slight

which may be taken as If inches. due to scaling in working the

loss

.

FORGING

44

which must be allowed

iron,

The amount

This

for.

is

of stock required in this case

Round Block

shaft

generally done by adding

minimum amount

a slight amount to the

required

A

If" 2"

B

C

Square shaft

If"

Total

When up with a

5f"

the forging

fuller,

each case.

in

would be about,

is

started, cuts,

which are afterward opened

may be made as shown by the upper

sketch in Fig. 79.

X

iz

\r Fig. 79.

In

this particular case

not absolutely necessary that exactly the

it is

proper amount of stock be taken, as

it

would be a very easy matter a

to take

fS

and trim 24'

tf--r

too

little

off

from the ends, forging

much surplus

the

after

the

was made.

Fig. 80.

shown

in

used.

This forging, which

Fig. 80, however,

is

would be started as shown 81,

and

is

it

the distance

it

is

the general shape of a connecting rod,

in Fig.

quite important that

=3^

=Cf

A be correct. The stock

used should be 2"

X

4".

Each end

will, of course, require just 6"

The

stock.

With the forging such as amount be

essential that the exact

center part

is

of

j\.

—H—

Fig. 81

a cyl-

inder 2" in diameter and 24" long, the volume of which would be \"

X

1"

X

3|

X

lh\ cubic inches.

24"

=

75f cubic inches, which For each inch in length the 2"

may be

X

taken as

4" stock would

FORGING

X

have a volume of 4" require 75^

=

8

-f-

2"

X

1"

=

45

Therefore

8 cubic inches.

it

would

9 Y\" of stock, to form the central piece, conseA in Fig. 81 will

quently the distance between the cuts shown at

be 9 T7짜V/

To

.

The

scaling.

this

V = 21 Ty.

Any

/

9T

might be added a

amount

total

may

Weight

may

forging

would be

+

6"

6"

+

generally be separated into simple

form the

cal-

any forging the

vol-

In

was done above.

parts of uniform shape as

culation

allowance for loss in

slight

of stock required

this

be easily made.

To

of Forging.

ume may first be found

in

find the weight of

cubic inches and

by

this multiplied

the weight of wrought iron per cubic inch.

If the forging

.2779,

be made

of steel, the figures .2936 should be used in place of .2779.

This

Below is given the weight of wrought both in pounds per cubic inch and per cubic

gives the weight in pounds. iron, cast iron

and

steel

foot.

Cast Iron

450 per cu.

ft.

"

"

Wrought Iron 480

in

B

1

The

.7 lbs.

to find the

^

has a volume of

made

of

forging

wrought iron in Fig.

and would weigh,

A much

easier

way

given on pages 46 and 47. flat

.2779 " .2936 "

.''

"

"

"

weight of the forging shown

C f cubic inch If the cubic inch, making a total of 2 || cubic inches.

forging were

inches

were required

A

Fig. 78.

and

it

.2604 per cu. inch.

" "

490 "

Steel

Suppose

"

iron bars.

of length of

When

if

it

cubic inch,

would weigh 2

80 has a

made

of

total

wrought

to calculate weights

The

first

In the second table

4-f

X

.2779

=

volume of 171 f cubic iron, 47.64 lbs. is

to use tables

such as

table gives the weights per foot of is

given the weights for each foot

round and square bars. using the table on page 46 to ascertain the weight of any

size of flat iron per foot of length, look in the first

for the thickness.

giving the width.

column

at the left

Then follow out in a horizontal line to the column The number given will be the weight in pounds

of cne foot of the desired size.

To use the table for

calculating weights, the procedure

would be

as

follows:

Taking Fig. 80 as an example, each end is 2" X 4" and 6" long and the two ends would be equal, as far as weight is concerned, to a bar

46

FORGING

WEIGHT OF FLAT ROLLED Length, 12 inches.

ta

00

J4

IRON.

FORGING

47

WEIGHTS OF ROUND AND SQUARE ROLLED

IRON.

Length, 12 Inches. H[Ot>

c3

o^ 2 U.S £ fl a

oCQo

o

5,3 feoi °f ps » a 53 a*S °

.013 .052 .117 .208 .326 .469 .638 .833 1.055 1.302 1.576

1.875 2.201 2.552 2.930 3.333 3.763 4.219 4.701 5.208 5.742 6.302 6.888 7.500 8.138 8.802 9.492 10.21 10.95 11.72 12.51 13.33 14.18 15.05 15.95 16.88 17.83 18.80 19.80 20.83

21.89 22.97

CO 0J <u

x

y a a .pf

3 v

fl

V o fl o t>tfOJ

.010 .041 .092 .164 .256 .368 .501

.654 .828 1.023 1.237 1.473 1.728

2.004 2.301 2.618 2.955 3.313 3.692 4.091 4.510 4.950

5.410 5.890 6.392 6.913 7.455 8.018 8.601 9.204 9.828 10.47 11.14 11.82 12.53 13.25 14.00 14.77 15.55 16.36 17.19 18.04

OlSH r, HH

ODr-j UJ fl

'Sqflo

-rH

24.08 25.21 26.37 27.55 28.76 30.00 31.26 32.55 33.87 35.21 36.58 37.97 39.39 40.83 42.30 43.80 45.33 46.88 48.45 50.05 51.68 53.33 55.01

56.72 58.45 60.21 61.99 63.80 65.64 67.50 69.39 71.30 73.24 75.21 77.20 79.22 81.26 83.33 85.43 87.55 89.70 91.88

18.91 19.80 20.71 21.64 22.59 23.56 24.55

25.57 26.60 27.65 28.73 29.82 30.94 32.07 33.23 34.40 35.60 36.82 38.05 39.31 40.59 41.89 43.21 44.55 45.91 47.29 48.69 50.11 51.55 53.01 54.50 56.00 57.52 59.07 60.63 62.22 63.82 65.45 67.10 68.76 70.45 72.16 73.89

3 a

|5.2

FORGING

48

ing

is

done

When

in a lathe or other machine,

a forging

more material should be left. amount of

calls for finish, in calculating the

stock, or weight, the dimensions taken should not

be the actual ones

Fig. 82.

shown by the drawing, but these dimensions with the proper allowance

made Crank

for finish.

Shafts.

There are several methods of forging crank shafts.

The more commonly used .in

detail below.

When

is

the commercial method, as described

forgings were mostly

made of wrought

iron, the

FOKGING When to the

the forging leaves the shop,

shape shown by the solid

49

will

it

left in

a shape similar

dimensions shown

The crank

here allowing for the necessary finishing. left in

be

lines in Fig. S3, the

itself

would be

a solid block, the throat being afterwards cut out as indicated

by the dotted

A

lines.

shown, and the removed by making two slits with a cold saw and the block then knocked out with a sledge hammer.

line of holes is first drilled as

block of metal to be taken out

is

It is possible to

form

this throat

chopping out the surplus

by

metal

with a hot chisel in the forge shop,

but on small cranks in particular, such as here shown,

it is

generally

cheaper in a well equipped shop to use the

first

The quired.

would require

no waste from

is

of

course to

the

As each inch of stock contains 6 cubic inches, of stock to form this end provided there was

10.13 cubic inches. it

step

amount of stock reThe long end would contain

calculate Fie. 85.

method.

first

1.7"

scale.

Waste does take

place, however,

be allowed for, so about 2" of stock should be taken.

and must

The

short

end contains 5.22 cubic inches and would require .87" of stock, without allowance for scale. About 1\" should be taken. The total stock then required would be

The

first

down with

may

is

to

make

the cuts, and spread the ends as

shown

These ends may then be forged

in Fig. 84.

or

step

7-|".

a sledge

hammer

as

illustrated

be worked out under the steam

hammer,

finishing

the

v 1

up against the

shoulders being done as illustrated in Fig. 85.

The

finished

taken

shaft

may

between

to

see

be rounded down and

swages.

that

Care must be

the cuts

are

properly

spread before drawing out the ends.

If the

cuts are left without spreading, the metal will act

the

manner shown

in

Fig. 86.

The

somewhat

top part of the bar, as

after it

is

FORGING

50

worked down,

will fold over

When

trated.

and leave a crack or

the metal starts to act in this

cold shut as illus-

way

the fault should

be corrected by trimming off the overlapping corner along the dotted line shown in the upper sketch.

When a crank

Multiple=Throw Cranks.

more than one

shaft has

Fig. 87.

crank or crank pin, double-throw crank

it

is

is

spoken of as a multiple-throw crank.

or triple throw, one with three cranks, etc.

tiple-throw cranks are forged

flat,

i.e.,

A

A three throw

a crank shaft with two cranks.

As a general

the cranks are

rule mul-

all

forged in

Fig. 88.

line

with each other.

The

shafts

and pins are then rough turned

and the cranks are heated and twisted into shape. The forging for the double-throw crank shown in Fig. 87 would first be made in the general shape

shown

in Fig. 88.

The parts shown by the dotted would then be cut out with a and saw

as

lines drill

above, and

described

the shafts and pins rough turned, i.e.,

turned round, but

The

as possible.

returned to the forge is

heated and the cranks twisted to the desired angle.

ing, the

A.

as large

left

forging

is

then

shop where

When

it

twist-

crank would be gripped just to the right of the point marked

This

may

be done with a

vise, or

wrench

if

the crank

is

small, or

FORGING it

may be

held under the steam

hammer.

51

The

twisting

may

be done

with a wrench similar to Fig. 89 which

may be

easily

made by bending up

U

a

and welding on a handle. Three-Throw Crank without any

of flat stock

A

bearings

intermediate 90. in

is

shown

in Fig.

The rough forging for this is shown Fig. 91. The extra metal is removed

by the dotted lines and the twisting done as described before. Weldless Rings. Rings and eyes as indicated

forged

made

make a

and

split

amount

may be done is

hammered

necessary, of

is

the

of

which

the

illusfirst

is

is

opened

into shape.

calculate

required.

This

The

step

first

area of the ring,

done by taking the area of the

is

outside circle,

and subtracting from

area of the inside

Area of outside "

bar

course, to

stock

as follows:

determine

to

flat

be

it

as

the ends, punched

as shown, this split

out and the ring It

ring such

A

Fig. 92.

in

forged rounding on

be

manner described

As an example, suppose

below.

required to trated

may

without any welds

solid

in the general

" inside

the

circle.

circle

"

rinff

The

it

stock used

12.57

sq.

m.

7.07 5.50

when making small

thin rings should be twice

FORGING

52

the width of the side of the ring to which of

an inch.

When

the bar

and when worked back

into

stock

is

is

added

the stock

is split

shape

is

is

at least one-quarter

more or

less

deformed

Although no

slightly thinned.

by the hammering, an allowance

lost

must be made for the thinning and stretching and it is necessary to make the stock slightly wider on this account, as noted

Allow-

above.

ing V' for hammering, and taking stock 1\" wide,

amount of stock required would be 5.5 -r- 1.5, Allowing a small amount for loss by scale, etc., 3f \" of stock should be taken. In making this calculation, the thickness of the stock the

equal to 3.66".

is

not taken into consideration, as the thickness of

Fig. 92.

the

This general method

where rings are

to

finished

ring

is

the

same

as

the

stock.

used on a large variety of work, particularly

is

be made of tool

steel

and should be made without

a weld.

Another method of making weldless mer,

is

illustrated

in

Fig. 93.

proper amount of stock into a disk, a hole

is

is first

punched

disk and a mandril inserted.

shaped

rest is

rings,

under the steam ham-

The forged

into this

A

U-

then placed on the anvil

laid

hammer and the mandril The ring is turned on on this.

the

mandril and forged into shape.

of the steam,

Fie. 93.

Larger and larger mandrils are substituted as the hole in the ring increases in size.

Lever with

Boss.

The

following

description

forgings of the

serve for

Fig. 95.

Fig. 94.

many

will

same general shape.

The

forging

shown

in

FORGING Fig.

of

94

will

be taken as an example.

making work

of this character.

One

53

There are two general ways is

to take stock of the proper

The other is to size for the lever and weld on a chunk for the boss. take stock large enough to form the boss and draw out either the entire Ks-^h

Fig. 96.

lever, or

a short stub, to which the lever

started for the

is

welded.

The work may be

method by doubling over the end of the stock as This is welded up and rounded by the same 95.

first

illustrated in Fig.

general method as afterwards described for the other boss.

The

Fig. 97.

second method of shaping

is

illustrated in Fig.

would be two inches square. The illustrated at A. The end is then drawn out

this case

as

B.

In drawing out the stock,

if

The

stock in

into the shape

made

shown

the metal be allowed to flatten

into shape like C, a "cold-shut" will

X

96.

fuller cut is first

at

down

be formed close to the boss, as the

and work into the metal, making a crack in the work. The proper way to draw out the stock is shown at D. The square piece left for the boss is rounded up over the corcorner at

will overlap

FORGING

54

to make the work way and straight 3ned after the forging is completed. The boss may be using a set hammer smoothed up by or swage in the manner indicated. Knuckles. One example of a very numerous

ner of the anvil as shown in Fig. 97.

end

easier to get at, the

<7^

§

Fie. 98.

is

Sometimes

bent back out of the

class of forgings

shown

is

of connecting rods, knuckle joints on valve rods,

^

as indicated

^-

method employed make such a forging is shown in Fig.

Two

fuller cuts are first

made

to

at A and the part for the shaft of the forging drawn out. The thick end is then punched and split, as indicated at B. This split end is

opened up and forged out

indicated in Fig. 100, the anvil.

the end being

if

the

work

and the

forging

done on

first

the steam

method hammer,

flattened

as

indicated

to the position

When drawn

ends are flattened out straight

shank with a

The

is

^

manner

in the

and then gradually tipped up shown by the dotted lines. across

the

Fig. 101 illustrates the

of working out under

to size, the

is

and various other

99.

A common

places.

This

in Fig. 98.

shape used for what are known as marine ends

finishing

done around the

fuller as indicated in Fig. 102. is

Fi S-

then bent into a U-shaped

loop of approximately the shape of the finished knuckle.

same dimension

iron the

finished knuckle

Fig. 104

may be

shaped by

Trim E,

method. quently Fig. 100.

wrench

suited for nuts of different sizes

flat

this

as

forg-

same general

simple

tool

that

is

fre-

This S wrench. usually made with a gap at each end

called is

down

shows other

Fig. 99, to the dotted line.

A

Wrenches.

bar of

inserted between the sides

is

in Fig. 103.

ings which

A

as the inside of the

of the loop, and the sides closed

shown

"•

for

It is

is

the

shown complete

in Fig. 105.

FORGING The

55

A line drawn

jaws at the end should be parallel with each other.

from one jaw

should

to the other

make an

There are two ways

center line of each.

angle of 30 degrees with the

which such a wrench can

in

Fig. 101.

One

be forged. the handle.

to forge the

is

In the other the jaws are cut from a solid piece of metal

and the iron between handle.

make

jaws separately and then weld to

The

latter

is is

then drawn

down

preferable,

since

to the proper size for the it

avoids

all

welds.

the wrench by the second process, select a piece of

To

steel large

U

e

^&5S

•47

Fig. 102

enough

to

Fig. 103.

form the head.

treat the other

a.

end

m

metal giving the

Fuller

Round

it

down back

the end and

of the

head as shown

punch the hole b. Next same way and draw out the intermediate form shown at B. Now cut out the holes b b securing a

in A, Fig. 106, at

the

FOKGING

56

shown at C. It now remains to bend the heads to the propangle and give the desired curve to the shank. In forging such

the form er

5i

ÂŤ=(C

o

qj

iittttth

Fig. 104.

a wrench the outer edges should be will

The

not cut the hand.

square with sharp edges.

slightly

rounded so that they

inside of the jaws should be perfectly

This

finish

can be best obtained by

filing.

Fig. 105.

Socket Wrenches are in is

"hurry up" work forged to the

same

is

the

size

made

in several ways.

method

The

easiest

way

A

stub

illustrated in Fig. 107.

and shape as the

finished hole

is

to be,

and

FORGING a ring, bent up of thin

welded round

flat iron,

ing the socket, a nut or bolt head of the

intended to

fit,

57

this stub.

same

When finish-

size that the

wrench

is

should be placed in the hole and the socket finished

Fig. 106.

over this

this,

kind

between swages. is

to

make a

A

way of making wrenches of same dimensions as the finsolid. The socket end is then

better

forging having the

ished wrench with the socket end

left

Fig. 107.

drilled to

a depth slightly greater than the socket

is

wanted.

The

diameter of the drilled hole should be as shown in Fig. 108, equal to the shortest

end

is

diameter of the finished hole.

After drilling, the socket

heated and a punch, of the same shape as the finished hole,

FORGING

58

driven into

The end

it.

the corners sharp.

of the punch should be square across and As the punch is driven in, it will shave off some

of the metal around the corners of the hole

and

force

it

to the

bottom,

Fig. 108.

thus making

it

necessary to have the drilled hole slightly deeper than

the finished socket.

The ladle shank shown in Fig. 109 may be made The ring may be welded up of flat stock and a round handle welded on with a T-weld. Or square stock may be Ladle Shank.

in several ways.

taken,

worked out and

split as

shown

ing without any welds at

all

be

indicated

the stock as

to split

in Fig.

and work out

Ill

same way take more

would in

that a weldless ring

The

made. 109.

make

Another method of mak-

the ring.

Fie;.

ends

in Fig. 110, these split

being afterwards welded to

the is

method would

latter

time but would

make

the sounder forging.

Molder's Trowel. is

The

molder's trowel

illustrated in

Fig.

112

a sample of a large class of forgings, having a wide, thin face with

The

a comparatively small thin stem forged at one end. for the trowel

would be about \"

X

V.

allow for the formation of a ridge at R.

This Fig. 113

is

stock used

thick enough to

shows the general

FOEGING

59

method employed. Two nicks are first made with fullers as illustrated at A and the stem drawn down, roughly, to size. This stem is then bent up at right angles and forged to a square corner as illus-

Fig. 110.

trated at B, in the

bracket

is

the ridge

formed.

shown

at

same general manner

When

as the square corner of a

flattening out the blade in order to leave

R, Fig. 112, the work should be held as shown at

=1

C, Fig. 113. is

Here the handle

held pointing

downward and

against the side of the anvil.

By

down on the work and covering the part directly striking

over the edge of the anvil with

Fig.

in.

the blows,

all

anvil will

be flattened down.

By

swinging the piece around

into a reversed position, the other edge of the blade

down.

the metal on the

is then thinned This leaves the small triangle shown by the dotted lines

FOKGING

60

un worked and forms the ridge shown

at

be obtained by placing the work

on the

set

flat

R.

The same

result could

anvil face

and using a

hammer.

TOOL STEEL WORK. Tool

Steel.

Although not

may

ordinary

strictly true technically, for

be considered simply a combination of iron

purposes tool

steel

and carbon.

The more common grade

contains perhaps

1

per cent

Fig. 112.

of carbon.

Machine

steel

and wrought iron do not contain

element carbon to any great extent.

machine

steel

If

this

a piece of wrought iron or

be heated red hot and suddenly cooled, the metal

mains practically as

re-

was before heating, but if a piece of tool steel be subjected to this treatment, it becomes very hard and brittle. By a modification of this heating and cooling, almost any degree of hardness

may be

it

imparted

to the steel.

When

tool steel

is

heated red hot

and then suddenly

cool-

becoming very hard,

ed,

the process

is

detailed

tempering,

the student

ferred to

as

explanations of

hardening, etc.,

known

For more

Hardening.

is

re-

"Tool Making",

as merely general state-

Fig. 11

ments and explanations will

be given here.

If

two pieces of

tool steel

be heated, one to a

comparatively high heat and one to a lower heat and the two pieces

suddenly cooled

in water, if the

ends be then snapped

difference will be noticed in the fractures.

The

off,

a decided

piece cooled from the

FOEGING

61

higher temperature will have a very coarse grain, while that cooled

from the lower temperature fixed

when hardening a

will

The hardness depends upon cooled. The more rapid the grain depends is

have a

of steel

when

cooling, the harder

upon the heat from which the This heat

is

known

and

is left

steel contains,

grain.

the steel

is

The

the steel.

There

steel is cooled.

be cooled and have the

A

as the hardening heat.

very hard and

.The hardening

Hardening.

may

things are

and

piece

hardening heat has an extremely

cooled from this

silky looking grain

carbon the

—hardness

the rapidity with which

only one heat from which the steel

proper grain.

Two

finer grain.

piece of tool steel

fine

brittle.

amount

heat varies with the

of

the greater the percentage of carbon, the

lower the hardening heat.

To to is

determine the hardening heat, a bar \" or f" square

then tested,

if

too hard to

file it

heated

is

This end

a good red heat on one end, and cooled in cold water.

has been hardened, and the heat

was cooled was either the proper hardening heat or some higher heat. If the end can be filed it was cooled from some heat below the hardening heat. If the end proves to be soft it should be rehardened by cooling from a higher heat, if hard it should be from which

broken

end

is

off

it

and the fracture examined.

very fine the steel

too hot

is

If the grain of the

properly hardened,

and the end should be rehardened

Any

the hardening heat will

than the

critical

make

is

make

was heated

The

ex-

able to give the steel

variation either above or below

the grain coarse.

heat will not

it

at a lower heat.

periment should be repeated until the operator a very fine grain every time.

coarse,

if

broken

A temperature lower

the steel as coarse in structure

as a temperature correspondingly higher, but there will be

some

difference.

Hardening Baths. Various baths are used for cooling steel when hardening, on account of the different rates at which they cool the heated metal. An oil bath is used when the steel is wanted tougher and not excessively hard, as the

oil cools

Brine or an acid bath are used when the

the steel slower than water. steel is

they absorb heat more rapidly than water.

work mercury, or heat very rapidly.

quicksilver,

is

wanted very hard, as For excessively hard

sometimes used, as

it

absorbs the

FORGING

62

Laws

General

of

The two

Hardening.

simple general facts of

hardening that must be remembered areas follows:

from which the

First, the

heat

cooled determines the grain secondly, the rapid;

determines the hardness, everything else being equal,

ity of cooling

the

steel is

more rapid

the cooling, the harder the steel.

When

Annealing.

by cooling the

steel is

annealed

it is

softened.

This

is

done

very slowly from the hardening heat, the cooling

steel

This cooling in some cases takes As noted under hardening, the rapidity of cooling determines the final hardness of the steel and if the steel be cooled very being done as slowly as possible. several days.

slowly

it

will

be

very soft; while

left

This difference

hard.

difference

The

from the same heat.

to

it

will

be

left

only

steel is the

details

Both should be done of various methods of annealing

Making".

Tools which are simply hardened

Tempering. are,

cooled rapidly,

between hardening and annealing.

are described in "Tool

above

if

taken to cool the

in the time

with few exceptions, too brittle for use and

reduce the brittleness.

Tools are always

left as

This process

hard as

it is

is

known

possible to leave

as

described

it is

necessary

as tempering.

them and

still

have them tough enough for the work for which they are intended. In reducing the brittleness of the

steel,

and tempering

necessity taken out

as a reduction of the hardness, but

of the brittleness.

some

of the hardness

is

of

therefore sometimes spoken of

it is

in reality,

merely a reduction

After a tool or piece of steel has been hardened,

of the brittleness

perature.

is

some

is

taken out by a slight reheating to a low tem-

These temperatures vary from 200°

F., to

about 650° F.

These temperatures are determined in various ways. The simplest and perhaps the most commonly used, is to polish the steel after it has been hardened and then reheat the part to be tempered until the surface shows a certain color. If

any bright piece of iron or

of about 400°

temperature it is

F

is

is

be heated, when a temperature

As the

increased this yellow grows darker until at about 500°

a decided brown.

on the surface.

steel

reached, the surface will turn pale yellow.

When 600° F is reached,

These

F

a deep blue color shows

by a thin scale which is and are no indication whatever of

colors are produced

formed on the surface of the

steel

hardness, merely showing to what heat steel or iron has been raised.

FORGING

63

tools may be divided into two general classes: First, which have one edge only tempered; second, those which are tempered throughout. To the first class belong most lathe tools,

Tempered

those

To

cold chisels, etc.

When is

the second class, taps, dies, milling cutters, etc.

tempering tools of the

heated than

is

ened by cooling

first class,

The

in water.

considerably more of the tool

The

wanted hardened. tool

cutting edge

then hard-

is

then taken from the water, the

is

hardened edge polished, and reheated by allowing the heat

down" from

the

body

the second class are

which

of the tool,

first

hardened by being heated

ening heat and then cooled completely.

and the temper drawn by placing the

The

Tools of

steel either

uniform hard-

to a

tool

"come

to

quite hot.

is still

then polished

is

over the

or on a

fire

piece of metal which has previously been heated red hot.

It is

solutely essential that the steel should be heated to a uniform

The

when hardened.

perature

no difference whatever

before the body of the tool

ening heat

hot, these overheated corners are almost

necessary to insure success in hardening operations.

Lead Bath.

To

insure uniformity in heating, various methods

and when the work

are used, is

is

Absolute uniformity in heating to the proper hard-

off.

is

show when being heated. If points or come to the hardening temperature parts to be hardened should

in color

corners of tools are allowed to

sure to crack

is

done on a large

generally done in a furnace fired with gas.

method

to heat the steel in a

is

in a pot or crucible, to the

the lead

is

bath of red hot lead.

hardening heat of the

must be

scale the heating

Another

common

The

is

heated

The

top of

lead

steel.

covered with powdered charcoal or coal to prevent the

When

formation of the slag or dross on top. it

ab-

tem-

perfectly clean, dry,

and

free

from

steel is

heated in lead

rust.

TOOL FORGING AND TEMPERING. Forging Heat. piece of scrap steel

Before attempting any work with tool is

to

several times at various heats until the manipulator effect of the various hearts

upon the grain

it

will stand.

When is

heavy forging

done upon a

tool,

is

to

is

of the steel.

should also be experimented with to determine just

rough shaping

steel,

a

be experimented with, heated and hardened

be done,

how

i. e.,

sure of the

The

steel

high a heat

when

the

first

a comparatively high heat should

FORGING

64

be used.

The

should be forged at about what might be called

steel

The

a good yellow heat.

lighter

hammering, when

be done at a lower heat, about the hardening heat.

hammering should be done below

finishing, should

Very

the hardening heat.

little, if

any,

If the grain

D D Fig. 114.

of the steel has heen raised

decidedly reduced by a

by too high a

little

hammering

heat, at

it

can generally be quite

some heat above the hard-

ening temperature.

Cold

The

Chisels.

stock should be heated to a good yellow

heat and forged into shape and finished as smoothly as possible.

When

n

properly forged, the end or cutting edge will bulge

out as shown in Fig. 114.

It is

a good plan to simply

nick this end across at the point where the finished

edge

is

come and then

to

pered, this nicked end

examined.

after the chisel has

may

Whenever

be broken

possible,

off

is

it

been tem-

and the grain

a good plan to

may be broken When hardening, a

leave an end of this sort on a tool that off after

the tempering

chisel should

-A

is

done.

be heated red hot about as far back from

the cutting edge as the point A, Fig. 115.

Care must

be taken to heat slowly enough to keep the part being heated at a uniform temperature throughout.

B

point becomes overheated,

water to cool

off,

it

but allowed to cool

in the air to

the hardening heat and then reheated

When Fig. 115.

more

below

carefully.

properly heated, the end should be hardened by

dipping in cold water to the point B. is

If the

should not be dipped in

cold, the chisel should

As soon

as the

end

be withdrawn from the water

and the end polished bright by rubbing with a piece of emery paper. The part of the chisel from A to B will still be red hot

FOKGING and the heat from

As

65

this part will gradually reheat the

hardened point.

this cold part is reheated, the polished surface will

showing

brown, and

at first yellow, then

change color

at last purple.

As soon

as

the purple (almost blue color) reaches the nick at the end, the chisel

Fig. 116.

The waste end may now be snapped

should be completely cooled. off

and the grain examined.

If the grain is too coarse the tool

be rehardened at a lower temperature, while

and the end bends without breaking,

it

if

the metal

is

should

too soft,

should be rehardened at a

higher temperature.

Cape seats, etc.

Chisel.

This

The end

is

for cutting grooves,

a chisel used

key

A should be wider than the rest of the blade back

Fig. 117.

to

B, Fig. 116.

end

is

chisel

is

started

by thinning down B with two shown at A, Fig. 117. The

then drawn out and finished with a

manner a cold

The

or over the horn of the anvil as

fullers,

illustrated at B. chisel.

A

cape chisel

is

hammer

or flatter in the

given the same temper as

FORGING

66

These two

Square and Round Nose Chisels. of

which are shown

the

same way

and tempered

in Fig. 118, are forged

the ends

chisels,

in practically

as the ordinary cape chisel, the only difference being in

Round nose cape chisels are sometimes used and are then known as centering chisels. The same general forms of lathe tools are used

the shape of the ends. for centering drills

Lathe Tools.

somewhat

in nearly all shops, but the shapes are altered

to suit in-

dividual tastes.

Right

Hand and

Left

Hand

Many

Tools.

lathe tools are

in pairs

and tool

and

left

hand

made

is

made

are called right

in

a

tools.

If

such a

way

that the cutting edge comes

toward the tool

is

left

hand

as the

held in position in

the lathe,

it

is

known

as a

hand tool, i. e., a tool begins a cut at the which Fig. 118. right hand end of the piece and moves from right to left is known as a right hand tool. The one commencing at the left hand end and cutting toward the right would be known as a left hand tool. The general shape of right and left right

hand

tools

for

the

same use

is

generally the

same excepting

that

the cutting edges are on opposite sides.

Clearance.

When making

all

lathe tools, care

must be taken

to

Section

A

B

Fig. 119.

see that they ject

beyond

have proper clearance,

i.

e.,

the cutting edge must pro-

or outside of the other parts of the tool.

the sides of the tool

must be undercut or

slant

In other words,

downwards and back-

wards away from the cutting edge. This is illustrated in the section A B of Fig. 119, where the lower edge of the tool is made considerably

FORGING

67

thinner than the upper edge, in order to give the proper clearance.

Round Nose and Thread

These

Tools.

The

general shape

is

shown

in Fig. 119.

tools are practically

way

the ends are ground.

When

hardening, the tools

alike excepting for a slight difference in the

should be heated about as far as the line A, Fig. 120, and cooled

up

to the line

The temper

B.

is

then drawn in the same general

way of

as described for tempering

cold

when a

chisels

excepting

light yellow color

at the cutting

that

shows

edge the tool

cooled for the second time.

is

All

lathe tools are given practically

the

same temper.

Sometimes Fig. 120.

much harder. well known plant

tools are left

one quite

In the tools are simply reheated until the

water evaporates from the cutting end, indicating a reheating to a

temperature of about 200째F. Cutting off Tools are forged with the blade either on one side or in the center of the stock.

The

easier

way

make them

to

the blade with one side flush with the side of the tool.

shown

in Fig. 121.

The

to forge

is

Such a

tool

is

cutting edge, A, the extreme tip of the blade,

should be wider than any other part of the thinned end, B. words, this edge should have clearance in in

all

In other

directions as indicated

The

drawing.

the

clear-

ance angle at the end of the tool as

shown

in the sketch, is

about correct for lathe

heavier

For

planer, the as

tools

angle

shown by the

tools.

for the

should line

X

be

X.

When hardening, the end of C C and cooled to about

the tool should be heated to about point the line

nose

D

tool.

Fig. 122.

D, and the temper drawn as described for the round Tools may be forged in the general way shown in

The

tool

is

started

by making a

fuller cut

as

shown

FORGING

68

After roughly shaping, the end

at A.

chisel along the dotted

line at

trimmed

is

with a hot

off

Great care must be taken to

C.

see that the blade of the tool has proper clearance in

directions.

all

Anvil Fig. 122.

When

a tool

is

wanted with a blade forged

by using two

in the center,

fullers instead of one,

first

started

cuts,

one on each side of the stock,

it

should be

then making two

in place of the single cut

shown

at A.

Fig. 123.

The general shape of this tool is shown

Boring Tool.

The

length of the thin end depends

which the

tool

is

to

upon the depth

in Fig. 123.

of the hole in

be used and as a general rule should be made as short

and thick as

possible, in

order to avoid springing. tool

may

general

The

be started in the same

way

as the

tool, the fuller cut

cutting off

being

made on

the edge of the stock instead of Fig. 124.

on the of the tool

is at

side.

The

cutting edge

the end of the small "nose," and this

"nose"

is

the only part which should be tempered.

Diamond

Points.

These

tools are

made

in a variety of modifica-

FOKGTNG

is

There are various methods

shape shown in Fig. 124.

tions of the

used for shaping them, one of which

shape

69

started as indicated at A.

shown, the end of the tool

is

is

After the nick has been

shaped as shown by the dotted

To

square up the end of the nose of the

worked backward and forward as indicated by trimming

off the

end

to the

it

The

at C.

tool

is

tool,

is

the

done it is

finished

proper angle with a hot chisel and touch-

up with a set hammer about as shown at D.

ing

lines,

Further shaping

blows coming in the direction of the arrow. as indicated at B.

The made as

illustrated in Fig. 125.

When

hardened

it

should be dipped

Side Tools or side finishing tools as they are sometimes called,

are generally

made

in

about the shape shown at F, Fig. 126.

The

tool

Fig. 125.

may be started by making a fuller

cut as

drawn out with a

shape B.

a set

hammer

The

tool

is

the blade.

fuller into the

the blade

is

shown

The end x

is

then

trued into shape along the dotted lines at C.

finished

by giving the proper

This

done by placing the

is

at A.

After smoothing up with

"offset" to the top tool flat side

edge of

down with

the

blade extending over, and the end of the blade next the shank about

beyond, the outside edge of the anvil.

A set hammer

is

Y

placed on the

blade close up to the shoulder and slightly tipped, so that the face of

FORGING

70

hammer touches the One or two light blows

the

and

after touching

When

thin edge of the blade only, as illustrated at D.

with the sledge will give the necessary offset

up the

blade, the tool

ready for tempering.

is

heating for hardening, the tool should be placed in the

fire

with

Fig. 126.

the edge.

way

more easy to avoid overheating The hardening should be done by dipping the tool in In

the cutting edge up.

this

it is

water as illustrated at E, only the small part surface.

The

tool

is

A being

left

above the

taken from the water, quickly rubbed bright

nnxo n Fig. 128.

Fig. 127.

on the

flat side,

light yellow.

color should

until the cutting

show the

edge shows a

entire length of the

If the color shows darker at one end, it indicates that end of the blade was not cooled enough and the tool should be

cutting edge. that

and the temper drawn

The same

FOKGING

71

rehardened, this time dipping the tool in such a

end of the blade which was too

The

Centering Tool.

soft before,

way

shown

centering tool

as to bring that

deeper in the water. in Fig. 127

used

is

on face-plate and chuck work. The end may be shaped by making a fuller cut and then flattening out the metal, for starting holes

trimming the cutting edge

Forming Tools

to

shape with the hot

chisel.

for Turret Lathes are

sometimes forged up in the same general shape as above and tempered like other lathe tools. This

Finishing Tool.

a

tool, Fig. 128,

same way

fuller cut or in the

as the

then flattened out and shaped with a set

may

be started either with

diamond

hammer

point.

as

shown

The end

is

in Fig. 129.

This generally leaves the end bent out too nearly straight, but

may

it

be easily bent back into shape as indicated

at

something of the

This bending

B.

will probably

leave the point

A

like C.

hammer

few blows

at the point indi-

cated by the arrow will give the tool the

ting

the

The

shape as at D.

edge should

same

as other

lathe

For planer and shaper this

shape, the end

more nearly

at right

the edge of the tool,

cut-

tempered

be

tools.

tools of

should be angles

to

making an

angle of about six or eight degrees less than the perpendicular.

In other words, the tool should have

less

end rake.

Flat Drills need no particular description as to forging ing.

and shap-

The size of the drill is determined by the width of the flat end

being the same size as the hole the

dimension were one inch, the

The drill

should be

drill

drill is

intended to bore.

would be known as a one-inch

made somewhat

softer

than lathe

tools,

being drawn until a light brown shows at the cutting edge. Springs are generally tempered in oil. The spring

,

this

If this drill.

the temper

is heated to a uniform hardening heat and hardened by cooling in oil. The temper is drawn by holding the spring, still covered with oil, over the

FORGING

72

flame of the forge, and heating until the If the spring is not

spring.

erally advisable, while heating

the

oil

bath, taking

it

oil

burns over the entire

uniform in section throughout,

it is

gen-

plunge every few seconds into

to

it,

out instantly and continuing the heating.

This

Fig. 130.

momentary plunge tends

to equalize the heat

by cooling the thinner

parts.

Lard

oil

or fish

in composition. off,

oil

are generally used as mineral

The above method

the blazing point of the

oil

The same

and heating

until

it

known

as blazing

results could

be obtained

turned blue.

Hammers.

mer

When making a ham-

the stock should be taken

large

make the largest part of the hammer without any upsetting. As a general rule the hammer is forgenough

Seer ion A. B.

is

too uncertain

being used to indicate the temperature

in place of the color of the scale.

by polishing the spring

of tempering

oil is

to

ed on the end of a bar and finished as completely as possible before cutting

off.

Hammer. About the easiest hammer to shape hammer shown at D, Fig. 4. This hammer, as well

Riveting riveting

other hammers,

shown

is

started

at A, Fig. 130.

by

first

punching the hole

When the eye is punched

is

as

the all

for the eye as

the stock

is

generally

bulged out sideways and in order to hold the shape of the eye while

FORGING flattening

down

a drift pin such as shown in Fig. 131

this bulge,

used.

This pin

ends.

The

made

is

73

larger in the center

is

and tapering at both same shape as the

center or larger part of the pin has the

finished eye of the

hammer.

This pin

is

driven into the punched hole

and the sides of the eye forged into shape as illustrated at B, Fig. 130. shape down made around The the bar where the face of the hammer will come, as shown at C. the manthen slightly tapered in face is end of the hammer toward the After the hammer has been as nearly as possible ner indicated at D. After the eye has been properly shaped, the next step

is

to

the tapering pene leaving the work, after a nick has been

finished,

is

cut from the bar

it is

the whole

and the

For tempering,

face trued up.

hammer is heated to an even hardening

heat.

The hammer

then grasped by placing one jaw of the tongs through the eye.

Both ends are tempered, this being done by hardeneng first one end and then the other. The small end is first hardened by dipping in the water as shown at

As soon

Fig. 132.

the position of the

reversed

and

hammer

the

color

scale appears

mer pene

is

cooled

instantly

in

the water the

for.

When

a dark brown

Fig. 132.

on the small end the ham-

again reversed bringing the large end

The

in the water.

drawn.

If the large

color appears

end

end

face

is

uppermost and the

then polished and the temper

properly hardened before the

is

temper

on the small end, the hammer may be taken complete-

ly out of the water, the large

on both ends at once. it is

is

polished and the temper

is

watched

is

is

end hardened.

face

"While the large end

smaller end

end

as this

promptly dipped

end polished, and the

colors

watched

for

As soon as one end shows the proper color in water, the other

end following as soon as

the color appears there, but under no circumstances should the eye

For some special work hammer faces

be cooled while

still

should be

harder, but for ordinary use the temper

above,

is

Ball

mer

is

left

red hot.

as given

very satisfactory.

Pene Hammer.

The

illustrated in Fig. 133.

general

method

of

making

this

After punching the hole, the

ham-

hammer

FOKGING

14:

is

roughed out by using the

end

is

shown

fullers as

A

at

The

and B.

ball

then rounded up, the octagonal parts shaped with the fullers

and the hammer cut from the bar, ground and tempered.

Ball

Fig. 133.

pene hammers the

same way

may

be

made

as described

hammer

with a steam

above, excepting steel

in practically

round bars of

that

should be substituted

for

the fullers.

Blacksmith's Tools such as

hammade in

cold chisels, hot chisels, set

mers and

are

flatters

much the same way as hammers. The wide face of the flatters may be upset by using a block such as is

Fie. 134.

shown

in Fig. 134.

end of the

tool

is

The

heated

dropped

into

the hole in the block and the face

upset into the wide shallow opening. in this

way.

Swages may

also

be worked up

FORGING Self=hardening Steel

much

for lathe tools,

75

used to a large extent in modern practice

is

being used in the shape of small square

held in special holders.

Such a

tool

hardening

name

indicates,

as

steel,

its

is

illustrated in Fig. 135.

steel is

to to

of

heat

red hot and allow

it

cooled in an air blast or

is

it

not necessary

It is

oil.

harden the

Sometimes the

to cool.

dipped in

Self-

self-hardening

almost

is

in nature, generally the only treatment that is required to steel being; to

steel

"draw the temper". The self-hardening quality of steel is given it by the addition of Chromium, Molybdenyum, Tungsten, or one that group of elements, in addition to the carbon which ordinary Self-hardening steel

tool steel contains.

'expensive grades. costing $1.00 or so.

much

steel will stand a

called

carbon

although

For

steel.

its first

cost

comparatively expensive,

is

and upwards per pound, some of the more

costing from 40 cents

is

When

in use, self-hardening

higher cutting speed than the ordinary sothis

reason

higher.

it is

much more economical to

use,

Self-hardening steel cannot be cut

with a cold chisel and must be either cut hot or nicked with

an

emery wheel and snapped off. Great care must be used in forging

it,

as the range of temperature

through which is

it

comparatively

may be slight,

from a good red heat ening steel

may be

p.

Some grades

to a yellow heat.

fire

135

running

annealed by heating the

the center of a good off together.

forged

and allowing the

steel to fire

a high heat in

and the

Steel which has been annealed in this

hardened by heating

of self-hard-

steel to cool

way may be

hardening heat and cooling in

to the

oil.

after

whom it is

This method of treating special grades was discovered some years ago by the men named. It was found that if a piece of self-hardening

steel

be heated

to a very high

Taylor=White Process. of self-hardening steel

and then suddenly cooled

to

temperature (about the welding heat)

about a low red heat, the

be in a condition to stand very heavier cut.

Steel treated in

edge of the tools almost burned or melted ing was necessary to bring

steel

would

much harder usage and take a much this way seemed to have the cutting

them

off

into shape.

and considerable grind-

When

put in use the

FORGING

76

edges would almost immediately be slightly rounded or crumble

but after this slight breaking

down

off,

would stand up under excessively trying conditions of high speed and heavy Tools of this character were of very little, or no, use for fine cut. finishing but were of great value for heavy and roughing cuts. of the cutting edge, the steel

,

HEAVY FORGING. An

Steam Hammer. in Fig. 136.

is

shown

an inverted steam cylinder,

whose piston rod the hammer head

is

The hammer

is

carrying the whole.

hammer

ordinary form of steam

Its essential parts are

attached, raised

and the frame

to

for

by admitting steam

Fig. 136.

beneath the piston.

The blow

is

dealt

beneath the piston and admitting

it

by exhausting the steam from

above the same.

The head

is

thus accelerated by gravity and the pressure of steam above the piston.

The

valve gear

is

so arranged that the intensity of the

varied by changing the

downward

stroke.

amount

The steam admitted below on

forms a cushion for the absorption In this

way

blow may be on its

of steam admitted to the piston

~>f

the

the

same stroke

momentum

of the head.

the lightest of taps and the heaviest of blows can be deliv-

FORGING

77

same hammer. These hammers are also made in a great variety of sizes. Steam hammers are rated by the weight of the falling A hammer parts, i. e., the piston rod, ram or head, and hammer die. in which these parts weigh 400 lbs. would be called a 400 lb. hammer. ered by the

Steam hammers are made in two distinct parts: the frame, carrying the hammer or ram, and the anvil, on which the hammer strikes.

ft

a Fig. 137.

The frame which

is

and the heavy

carried on a heavy foundation,

is

made of cast iron and upon a heavier foundation

generally

tool steel, rests

The

ped with a timber.

fitted

anvil,

with a die block of

of timber or

masonry cap-

object of these separate foundations

is

to

allow the anvil to give slightly under a blow without disturbing the

frame. times

On

made

very light power

hammers

the anvil

Hammer

Dies.

The

dies, as

most commonly used with a steam

Fig. 138.

hammer, have dies

and frame are some-

together.

•

Fig. 139.

The best ones are made of tool steel. These and left unhardened, then when the out of shape from use, they may be trued up

flat faces.

may be made

of tool steel

become battered and refaced without going to the trouble of annealing and hardening. Dies of gray cast iron and cast iron with a chilled face are also quite

dies

commonly

used.

Ordinary gray cast iron

is

used, particularly

when

FOKGING

78

shaped dies are employed for welding and light bending. Tongs for steam hammer work should always carefully be fitted

special

and should grip the stock firmly on at least three sides. mon shape for tongs for heavy work is shown in Fig. the tongs securely on the

a link

is

work and

to

make

it

sometimes used of the shape shown.

Fig. 140.

A quite com137.

To

hold

easier to handle them,

This

is

driven firmly

Fig. 141.

over the handles of the tongs and the projecting ends are used as

handles for turning the work.

Hammer

The common shape for hot chisels for use under the steam hammer is given in Fig. 138. The handle and blade Sometimes the are sometimes made from one piece of tool steel. blade is made of tool steel and an iron handle welded on as shown in The handle next to the blade should be flattened out the sketch. to form sort of a spring which permits a little give when using the Chisels.

B

Fig. 142.

The edge of the chisel should be left square across and not The proper shape is shown at A, Fig. 139. Sometimes special work the edge may be slightly beveled as at B or C. For

chisel.

rounding. for

cutting or nicking bars cold, a chisel similar in shape to Fig. 140

sometimes used.

This

is

made

crushing effect of heavy blows. similar in shape to Fig. 141

is

very

flat

and stumpy

For cutting into corners a

sometimes used.

is

to resist the chisel

For bent or irregular

work the chisel may be formed accordingly. For cutting off hot stock the method used is about as illustrated in Fig. 142, i. e., the work is The bar is then turned over and cut nearly through as shown at A. a thin strip of steel with square corners placed on top as shown at B.

FORGING

79

A

quick heavy blow of the hammer drives this steel bar through the work and carries away the thin fin shown, leaving both of the cut ends clean and smooth. Tools. The tools used for steam hammer work are generally Swages for finishing work up to three. or four inches very simple. in diameter are commonly made in the shape shown in Fig. 143.

Fig. 143.

The handle in

is

made

in the

shape of a spring and

may

one piece with the blocks and drawn out as shown

inserted as

Another

shown

sort of

at B.

This

sort of a tool is

swage sometimes used,

is

known

be either made

at C, or

may

be

as a spring tool.

illustrated in Fig. 144, the

Fig. 144.

top swage at A, the bottom swage at B.

This sort of a swage

is

used

on a die block which has a square hole cut in its face similar to the hardy hole in an anvil. The short horn X, of the swage, fits into this hole, the other

two projections coming over the side of the anvil block.

Tapering and Fullering Tool.

mer

dies are flat

and

parallel

and

The it is,

faces of the anvil

and ham-

of course, impossible to finish

FORGING

80

tapering

work smooth between the bare

by using a

tool similar to Fig. 145.

Its

This work may be done

dies.

method

of use

is

shown

down and

146, the roughing being done with the round side

in Fig.

the finish-

Fig. 145.

ing with the

flat side.

seldom employed their place in the

in

hand

Fullers used for ordinary

steam hammer work.

manner

Round

illustrated in Fig. 147.

on one side only, simply one round bar be taken to be sure that the work

is

is

If

a nick

wanted

is

Care must always

used.

in the

forgings are

bars are used in

proper position before

Finishing

Roughing Fig. 146.

striking a

heavy blow with the hammer.

should be brought to

a

flat

down

"bearing" for the

lightly first

To do

this the

blow.

Squaring up Work.

happens that work

\

/

sided

under

worked up as

shown

the into

is

It frequently

knocked lop-

hammer, being some such shape

at A, Fig. 148.

To

to

this

shape

B and

then rolled in the

by the arrow until shaped as at C when then be worked down square and finished like D. Crank Shafts. The crank shaft shown in Figs. 82 and 83 direction indicated

cor-

and bring the work up square, the bar should be put under the hammer and there knocked in-

rect

Fie. 147.

hammer

on the work thus bringing the piece

it

may

is

quite

FORGING a

81

common example of steam hammer work.

as illustrated in Fig. 149, the cuts being

A

special tool

is

used for

D

OOD Fig. 148.

this as illustrated.

When first

flattening

the cuts are very

be made with a hot

After the ends

are

out, the corners next

may be

to the cheeks

using a block as

squared by

shown

Connecting Rod

illustrated

I

in Fig. 85.

Drawing

:

The

out between the shoulders.

forging

worked

chisel

doubling over and forming a "cold shut".

hammered

is first

and then opened up with this spreadWith light cuts, however, both ing tool. operations may be done with a spreading Care must be taken, tool at the same time. of the material from prevent any io ends, out the

/?

when

stock

on each side of the crank cheek.

deep, they should

B

The

Fig.

in

80,

while hardly the exact proporof the connecting rod,

tions

is

near enough the proper shape to

of this The work is

give a good example

kind first

of forging. started

by making two cuts

The

as illustrated in Fig. 150.

metal between the two cuts then drawn out by

is

using two

blocks as shown in Fig. 151

steel

until the

metal

is

stretched long Fig. 149.

enough

to allow

the corners

of

the square ends to clear the edges of

work

is

done

directly

upon

the

hammer

dies,

when

the

the bare die.

MISCELLANEOUS PROCESSES. Shrinking.

cooled in

it

iron

shaft.

is

its

heated

it

original size.

expands and upon being This property

is

utilized

known as shrinking. Fig. 152 shows a collar shrunk The collar and shaft are made separate, the hole through

doing what

on a

When

contracts to about is

the collar being slightly less in diameter than the outside diameter of

FORGING

82

The

the shaft.

collar

collar to expand,

is

then heated red hot and the heat causes the

making the hole

larger in diameter than the shaft.

The collar,

while still hot, is then placed on the shaft in proper position, and cooled as quickly as possible by pouring water on it. As the collar

3 ^v ^^ ZI Fig. 151.

Fig. 150. •is

cooled

it

contracts

and squeezes, or

This principle of shrinking fit is

is

locks, itself firmly in position.

used to a large extent where a firm, tight

wanted, the only objection being that

a piece

off after

Brazing.

it

it is

rather difficult to take

has once been shrunk into place.

When

two pieces of iron or

steel are

welded together,

Fig. 152.

they are joined by making the pieces so hot that the particles of one piece will stick to those of the other, no

them.

medium being used

to join

In brazing, however, the brass acts in joining two pieces of

metal together in somewhat the same manner that glue does in joining

two pieces of wood.

Briefly the process

is

as follows:

The

surfaces

FORGING to

83

be joined are cleaned, held together by a suitable clamp, heated to

the temperature of melting brass, flux added, and the brass melted

The

into the joint.

This

is

brass used

is

generally in the shape of "spelter".

a finely granulated brass which melts at a comparatively low "Spelter" comes in several grades designated by hard,

temperature.

Brass Wire,

Fig. 153. soft,

etc.,

the harder spelters melting at higher heat but

stronger joint.

making a

Brass wire or strips of rolled brass are sometimes

used in place of spelter, brass wire in particular being very convenient in

many

153,

A simple example of a brazed

places.

where a flange

is

joint

is

shown

brazed to the end of a small pipe.

in Fig.

It is

not

necessary in this case to use any clamps as the pieces will hold them-

The joint between the two should be made roughly. If a tight selves together.

joint

be used there

the brass to run in. in spots but not

ting the to

all

will

be no chance for

The

joint should

fit

Before put-

around.

two pieces together, the surfaces

be joined should be cleaned

loose dirt

and

scale.

brazing the joint

is

When

free

from

ready for

smeared with a

flux

(one part salammoniac, six or eight parts

borax) which

may be added

Fig. 154.

dry or put on

form of a paste mixed with water. The joint is then heated and the spelter mixed with flux sprinkled on and melted into place. Brass wire could be used in place of the spelter in the manner in the

indicated, the wire being bent into a ring as shown.

as

Ordinary borax

may be

good as the mixture used above.

and

laid

used as a

The

round the

flux,

joint

although not

heat should be gradu-

FOKGING

84

ally raised until the brass melts joint,

when

and runs

around and into the

all

the piece should be lifted from the

cleaned by scraping

the melted borax and

off

fire

and thoroughly It

scale.

is

neces

sary to remove the borax, it

leaves

a hard glassy

scale

which

is

as

disagreeable

if

particularly

any

filing

or finishing has to be done to

the

joint.

This scale

may be

loosened by plung-

ing the

work while

still

hot, into cold water.

Fig. 155.

most any metal that stand the heat,

may

be brazed.

red Alwill

Great care must be used in braz-

ing cast iron to have the surfaces in contact properly cleaned to

and then properly

start with,

from the oxidizing

protected

influences of the air

and

fire

while being heated.

Copper

and

may be done by

heat-

Annealing Brass

ing the metals to a red heat

and then cooling suddenly cold water.

When

brass

is

hammered

tent,

it

becomes

springy and

if

any ex-

and

hard

has to be

it

further worked,

copper to

in or.

must be an-

it

nealed or softened, otherwise it is

almost sure to

split.

Bending Cast Iron. sometimes

It is

necessary

to

straighten a casting which h

become warped Cast iron

may

or

Fig. 156.

be twisted or

bent to quite an extent generally

s

twisted.

if

worked

cautiously.

The bending may

be done at about the ordinary hardening heat of tool

FORGING

85

and should be done by a steadily applied pressure, not by There is more danger of breaking the work by working it at

steel

blows.

As an example of how may be twisted, a bar of gray cast iron one inch square and a foot long may be twisted through about 90째, before it will break. Case=Hardening. The essential difference between machine too high a heat than by working at too low. iron

and

steel

tool steel

bon be added

is

the

machine

to

amount steel

of carbon that they contain. will

it

be turned into tool

steel.

If car-

Some-

times articles are wanted very hard on the surface to resist wear and at the

made

same time very tough of tool

enough, of

it

machine

will

be too

steel in

be too

will

to withstand shocks.

in order

steel

brittle,

If the piece

be

be hard

to

and

made

if

order to be tough enough,

To overcome

soft.

culty the parts are

made

and then the outside

is

of

this diffi-

machine

steel

carbonized or con-

verted into tool steel to a slight depth, and this outside coating of tool steel

ened. ing.

then hard-

The process is known as case-hardenThe method used generally consists of

heating the machine steel red hot in contact

iB

with something very rich in carbon, generally

ground

machine

bone.

steel takes

The

surface of

the

up or absorbs the

carFig. 157.

bon and is converted into tool steel. For more detailed information the reader is referred to collapse

and

sides of the pipe

if

this collapsing

One way

flat

plates as

same distance apart

may be

of doing this

shown

successfully bent into

would be

to

bend the pipe

in Fig. 154, the plates being the

as the outside diameter of the pipe.

large pipe, the sides are sometimes prevented in with a flatter.

Where

a tendency

can be prevented by keeping the

from spreading, a pipe

almost any shape.

between two

"Tool Making".

to

A piece of pipe when bent always has

Pipe Bending.

a single piece

is

to

In bending

from bulging by working

be bent,

it

may be done by

heating the pipe and inserting one end in one of the holes in a swage

block as shown in Fig. 155, the pipe being then bent by bearing

on the

free end.

As soon

as a slight

bend

is

made

it

is

down

generally

FORGING

86

necessary to lay the pipe

with a

flat on"

Where many

flatter.

such as shown in Fig. 156

shape that the pipe

is

is

the anvil and

work down the bulge

pieces are to be bent, a grooved "jig"

sometimes used.

The

jig is of

completely surrounded where

it is

thus not having any opportunity to collapse or bulge.

such a

being bent,

Pipe

is

some-

Fig. 158.

times

filled

full

Care must be taken

to see that the pipe

is full

For bending thin copper tubing,

solidly plugged.

with melted rosin.

it

may be

This gives very satisfactory results for

After bending, the rosin

acter of work.

to some extent. and that the ends are

This helps

of sand for bending.

is

filled

this char-

removed by simply heating

the pipe.

Duplicate in a

Work.

shop that

is

Where

several pieces are to be exactly alike

not equipped for special work, practical

to

the operations. "jig"

may

blocks.

it

is

sometimes

use a "jig" for performing

For simple bending the

consist of a set of cast-iron

Fig. 157 illustrates a simple

bend

with the block used for doing the work.

The work

is

done as shown

piece to be bent

is

at B.

placed, as

The

shown by

the dotted lines, with the bending block

on

Fig. 159.

top.

The bending

is

done by one or For

two strokes of the steam hammer.

convenience in handling, the bending blocks are sometimes held by a spring handle as for

shown

The blocks in this case are The handle is simply a piece of

in Fig. 158.

bending the hooks shown at A.

FOKGING

87

Y round iron with the ends screwed into the cast-iron blocks and held firmly

by the lock nuts shown.

This makes a cheap arrangement for

a variety of work, as the same handles

|X

,v,-k i

\

may

be used on various

sets of

FORGING For the second step the ball is flattened to about the thickness of the finished eye and the hole punched under the steam hammer with an

The

ordinary punch, leaving the work as shown at C.

This die

final

so shaped that

shaping

when the

is done with the finishing die D. two parts are together, the hole left is exactly the shape of the finished In the first die it will be noticed that the holes do not conforging. is

form exactly to the desired shape of the forging, being, instead of semi-

^

::.:-

Fig. 163.

Fig. 162.

circular, considerably

rounded

clearly in Fig. 1G1 at A,

off at

the edges.

where the dotted

lines

forging, the solid lines the shape of the die. is

this:

This

show

The

metal being forced out between the

When

the bar

is

turned these

flat

being larger

left like

faces of the die

fins are

shown more

object of the above

If the hole is semicircular in section, the stock,

than the smaller parts of the hole, after a blow will be

fins.

is

the shape of the

B, the

and forming

worked back and make a

FORGING "cold shut".

When

the hole

be formed like C, and

may

is

89

a modified semicircle the stock will

be turned and worked without danger of

Dies for this kind of work are sometimes

"cold shuts".

made

of

cast iron.'

When made

them

A "master" forging is first make of tool steel to exactly the

hot.

of tool steel

shape of the required forging. with

flat faces.

The

it is

sometimes possible

to

shape

blocks for the dies are then forged

These blocks are fastened

to the

handle and then

Fig. 164.

The master forging is then placed between the dies hammered doWn tight over the forging. This leaves a

heated red hot.

and the

dies

cavity just the shape for the required forging.

MANUFACTURING. The manufacturing shop shop.

differs

very essentially from the jobbing

In the latter shop very few forgings are

made

time exactly alike, while in manufacturing, each forging duplicated a large

number

of times

and

special

at the is

same

generally

machines are used for

doing the work.

Drop Forges are used out of wrought iron or

for quickly

steel.

They

forming complicated shapes

consist, as the

name

indicates,

FORGING

90

of a head that

may

be "dropped" from any desired height upon the

The head of the drop and the anvil are in the As they come together the metal is forced to flow so as to fill the interstices and thus take on the form desired. In drop forging the metal must be heated to a high temperature so as to be in a soft and plastic condition. piece to be shaped.

form of

dies.

A common is

shown

and

is

hammer used for this kind of work is The hammer in this case is fastened to a board

type of drop

in Fig. 162.

raised

by the

frame

it is

the frame being

friction rollers at the top of

pressed against the board.

When

the

dropped by releasing the

hammer

rollers

reaches the top of the

from the board.

may

This

Fig. 165.

be done automatically or by a foot treadle. built in the

same general way

as steam

Drop hammers

hammers.

are also

Dies for

drop

forging generally consist of a roughing or breaking-down die where the rough stock

is first

smoothing die when

given approximately the desired shape and a

tb<3

finishing

same Power Hammers. Another

is

done.

These

dies

have in

faces, holes of the

tool

which

is

used to quite a large

extent in manufacturing as well as in the jobbing shop

hammer.

This

is

quick, rapid blow

general types are

their

shape as the required forging.

made

is

in several different types

wanted.

shown

and

is

is

These hammers are run by

in Figs. 163

and

164.

The

the power

used where a belts.

first is

Two

known

as a

FORGING justice

The second

hammer.

is

91

a Bradley.

Shaped

dies are fre-

quently used on these hammers.

This

Bulldozer.

a tool used for bending and consists of a

is

heavy cast-iron bed with a block or bolster at one end, and a moving slides back and forth on the bed. A common type is shown in Fig. 165. Heavy dies are clamped against the bolster and on the moving head, of such a shape and in such a way that when the moving head is nearest the bol-

head which

shape

the

ster,

two dies

between the

left

shape

the

exactly

is

to

bend the In operation, the moving stock. head slides back and forth on the which

The

bed.

desired

is

it

to

bar to be bent

is

heated

and placed between the dies when the head is farthest from the bolster.

A

clutch

is

then thrown in and the

head moves forward bending the iron as

to the bolster,

it

goes.

same purpose hammers. They do the work as drop The class more slowly, however. of work is, in some respects, the Presses serve the

The

same. in

principal difference

lies

shape that

of

peculiarities

re-

quire different time intervals for the flow

shape

fill

is

move

slowly in order to acquire

its

the die, the press should be used.

Flanging Press.

This

Fig. 166.

the

such that the metal must

is

new shape or press.

Where

metal.

the

of

A particular type of forging press is the flanging

used more particularly in boiler work and

a heavy hydraulic press.

The

is

generally

done by placing the heated metal on the bed of the press and closing the dies together by hydraulic

flanging

is

pressure.

Cranes.

Where heavy work

is

to

be handled,

it is

necessary to

have some means of conveying the work from one part of the shop to another.

This

is

done by means of cranes of two general

types.

The

FORGING

92

traveling crane

and

jib crane.

The former

head track from one end of the shop latter

type

mers, and

boom swinging around

merely an arm or

a post and having

When

a suitable arrangement for raising and lowering the work.

handling heavy work, whenever possible, crane by

The

used more commonly for handling work under the ham-

is

is

type runs on an over-

to the other, generally.

center, in such a

its

way

that

suspended from the