NUTS

What are twin nuts and how do they function?

A twin nut is a unique type of fastener that can be split into two halves for quick assembly or adjustments of an application.

TWIN OR SPLIT NUTS ARE

A nut is a mechanical fastener with a threaded hole. It’s used with a bolt, screw, or stud to provide a clamping force and prevent axial movement.

Typically, a bolt is inserted through two parts with aligned holes and a nut is then screwed onto the bolt. The shaft of the bolt prevents radial movement of the parts while both the head of the bolt and the nut prevent axial movement.

The most common type of nut is the hex nut. It has a hexagonal outer shape for the faces of tools to apply torque when fastening. The hex nut is typically a good go-to option for many basic assemblies. However, there are also several types of nuts available to suit the needs of di erent applications. One such option is the twin nut, which is a type of split nut that resembles a regular hex nut that’s cut into two pieces for quick assembly and rapid adjustment. The two halves lock together so that they can function as a typical nut. To secure the nut to a bolt, it’s typically fitted with a conical washer.

Twin or split nuts are ideal for applications that require the addition of a structural nut to any bolt, rod, or

threaded shaft where there’s no access to the other end of the part. Installation on a bolt, rod, or shaft can be done without the disassembly of these fasteners. The split feature of the twin nut means it splits into two, identical halves along a plane that passes through the axis of rotation. This allows the female thread to be opened and placed around the male thread. It can, then, be used to insert the nut onto a leadscrew, which has no accessible end. Alternatively, this allows the nut to be opened so that it can move axially along a screw without any relative rotation — and then closed IDEAL FOR APPLICATIONS THAT at a new position (so that the screw actuation can resume). This can be REQUIRE THE ADDITION OF A useful in positioning applications, such as the leadscrew of a lathe, allowing a quick, rough setting before STRUCTURAL NUT TO ANY BOLT, the final adjustments are made. Split nuts used in these types of ROD, OR THREADED SHAFT positioning applications are usually made with machined parts and have WHERE THERE’S NO ACCESS TO additional mounting interfaces for secure attachment. They typically have THE OTHER END OF THE PART. threads cut to match the leadscrew of the machine. For this reason, these fasteners can be more costly to manufacture. The ability to separate the nut and place it at an arbitrary location and along a long, threaded shaft can be particularly useful for clamping and tooling adjustment operations.

Advantages of twin (split) nuts: • Easy to install • Disassembly of the bolt or shaft is not required • Greater inherent strength • Improved thread load distribution • Reduced tensile bending stress and bending at the thread root

The term, “twin nuts,” can also refer to the combination of a jam or half nut that’s used with a regular nut and as a form of friction (like a lock nut). A jam nut is typically used when it’s necessary to lock a nut into place without clamping to another object. It’s used to resist loosening under vibration and torque.

Take your pick

Nuts are the mating part in the assembly of a bolt and are used in many di erent applications, from basic furniture assembly to complex automotive or aerospace requirements and many others.

There are several types of nuts available, including specialty options, depending on the application. Consult with your fastener supplier to determine the ideal choice for your application. Here are a few options:

Barrel or dowel nut: has a cylindrical shape that can be inserted into a hole, which runs perpendicular to the axis of the bolt.

Cage nut: a type of captive nut that can be attached to thin materials, such as sheet metal, allowing bolts to be fastened in inaccessible spaces.

Cap nut: also called an acorn nut (because of its shape), it has a domed top to prevent contact with external threads.

Castellated nut: works as a locking device that’s resistant to movement and vibration and can be readily removed. Also called a castle or slotted nut, it’s typically used with cotter pins to prevent loosening. Coupling nut: an elongated nut that allows two threaded shafts to be joined coaxially.

Flange nut: has a wide fl ange at one end, which serves as an integrated washer to prevent movement. Serrated fl anges work to distribute force or pressure on the nut over the part being secured and ensure a locking action.

Keps or k-nut: designed to make assembly easier, it includes an attached free-spinning, lock washer.

Knurled nut: has a large textured (or “knurled”) diameter and is designed to be hand-tightened.

Square nut: a four-sided (square) nut that may be fl at or beveled on top, providing a greater surface contact area — which o ers greater resistance to loosening.

T-nut: used to fasten wood or particle board, it has a thin body with a fl ange at one end that resembles a “T.”

Wing nut: has two “wings” on each side, which allow it to be easily tightened and loosened by hand without tools.

The simple installation of a wing nut — no tools are required.