Troubleshooting Drilling

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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