Drilling tools
Troubleshooting drilling tools Problems and their causes
1 Cutting edge built-up
• cutting speed too low • excessive honing of cutting lip • when bright finish cutting lips have tool coated
2 Crumbling of outer corner
• non rigid conditions, insufficient workpiece clamping • deviation from concentricity too large • when interrupted cut reduce feed
3 Heavy wear and tear at flank
• cutting speed too high • feed too low • clearance angle too small
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4 Crumbling on cutting lips
• non rigid conditions, insufficient workpiece clamping • when interrupted cut reduce feed • max. wear and tear values have been exceeded • wrong tool type
5 Land wear
• non rigid conditions, insufficient workpiece clamping • deviation from concentricity too large • back taper too small • wrong coolant (oil), soluble oil too thin
6 Scoring on tool body
• non rigid conditions, insufficient workpiece clamping • deviation from concentricity too large • when interrupted cut reduce feed • for abrasive materials thicken soluble oil if necessary
7 Heavy chisel edge wear and tear
10 Misalignment, axis shifting Ø
• cutting speed too low • feed too high • excessive honing of cutting lip
8 Crumbling at intersection web thinningand cutting lip
• clearance angle too small • excessive honing of cutting lip • wrong tool type
9 Plastic deformation of outer corner
• non rigid conditions, insufficient workpiece clamping • deviation from concentricity too large • when spotting area transverse use milling cutter (two-fluted) for spotting • chisel edge too large
11 Heavy burring on breakthrough
• feed too high • max. wear and tear values have been exceeded • excessive honing of cutting lip
12 Unsatisfactory surface finish Ra
• cutting speed too high • insufficient coolant; increase coolant (volume, pressure) • incorrect or no corner chamfer
• non rigid conditions, insufficient workpiece clamping • deviation from concentricity too large • insufficient coolant; increase coolant (volume, pressure)
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