Types of wear on HSS and solid carbide drills
Splintering on edges
Cause
- Workpiece moves when the drill enters the material (e.g. workpiece is not clamped properly)
- Insufficient cooling
- Runout error too large
Solutions
- Check clamping element (check for play in the spindle unit)
- Check coolant supply
- Optimise runout
Splintering on guide lands
Cause
- Movement of the workpiece
- Incorrect handling or transport
Solutions
- Check workpiece clamping and tool stability
- Use original packaging for storage and transport
Splintering on steps
Cause
- Insufficient stability
- Chuck is not strong or precise enough
Solutions
- Check clamping device
- Use high-precision chucks
Built-up edge
Cause
- Cutting speed too low
- Negative bevel on cutting edges
- Insufficient cooling
Solutions
- Increase cutting speed
- Use a drill with sharper cutting edge preparation
- Check coolant supply
Chipping on guide lands
Cause
- Workpiece is moving when the drill exits the material; "springback"
- Insufficient cooling
Solutions
- Check workpiece clamping
- Check coolant, increase coolant pressure
Chipping on main cutting edge
Cause
- Unstable drilling conditions
- Interrupted cut
- Maximum wear width exceeded
Solutions
- Optimise workpiece and tool clamping
- Reduce feed rate
- Change tool earlier
Cratering
Cause
- Cutting speed to low
- Insufficient cooling
Solutions
- Increase cutting speed
- Increase coolant pressure
Point angle fragmentation
Cause
- Feed rate too low
- Drill not running true
Solutions
- Increase feed rate
- Runout < 0.02 mm
Excessive flank wear on the cutting edge
Cause
- Cutting speed too high
- Feed rate too low
- Insufficient cooling
- Drilling from two sides or interrupted cut on exit from material
Solutions
- Reduce cutting speed
- Increase feed rate
- Use higher-quality coolant (higher concentration, increase pressure, nozzle placement?)
- Check drill exit from material
Excessive wear on the cutting edge
Cause
- Cutting speed too high
- Coolant pressure too low
- Drill not running true
Solutions
- Reduce cutting speed, increase feed rate
- Increase coolant pressure
- Runout < 0.02 mm