Drills

Wear on outer tips

Reduce cutting speed [Vc]
Increase feed rate [s]
Adjust coolant flow direction
Increase coolant pressure

Cutting edge distortion of the cross cutting blade

Check tool clamping and throw
Check workpiece clamping
Check tip centrality and cutting edge height
Increase feed rate [s]

Breaking of cutting edges

Check tool clamping and throw
Check workpiece clamping
Reduce cutting speed [Vc]
Reduce tip relief
Increase grinding

Cracking of side spines

Check workpiece clamping
Increase back taper
Check tool clamping and runout
When packing chips, use a more open helix groove or drill intermittently (HSS/HSSCo only)
Slow down helical drilling, horizontal drilling
Increase feed rate [s]
Reduce feed rate when spot drilling
Adjust coolant flow direction
Increase coolant pressure

Larger hole diameter

Increase cutting speed [Vc]
Decrease feed rate [s]
Check workpiece clamping
Check tool clamping and runout
When packing chips, use a more open helix groove or drill intermittently (HSS / HSSCo only)
Check tip centrality and cutting edge height

Insufficient hole size

Adjust coolant flow direction
Reduce cutting speed [Vc]
Increase feed rate [s]
Check drill diameter

Oval hole

Check workpiece clamping
Check tool clamping and throw
Check tip centrality and cutting edge height
When packing chips, use a more open helix groove or drill intermittently (HSS/HSSCo only)

Breaking the drill bit

Check workpiece clamping
Check tool clamping and runout
When packing chips, use a more open helix groove or drill intermittently (HSS / HSSCo only)
Reduce cutting speed [Vc]
Increase feed rate [s]
Adjust coolant flow direction
Increase coolant pressure