Types of wear on HSS and solid carbide drills

Splintering on edges

Causes

  • 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

Causes

  • 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

Causes

  • Insufficient stability
  • Chuck is not strong or precise enough

Solutions

  • Check clamping device
  • Use high-precision chucks

Built-up edge

Causes

  • 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

Edge breakage on guide lands

Causes

  • Workpiece is moving when the drill exits the material: "springback"
  • Insufficient cooling

Solutions

  • Check workpiece clamping
  • Check coolant, increase coolant pressure

Edge breakage on main cutting edge

Causes

  • Unstable drilling conditions
  • Interrupted cut
  • Maximum wear width exceeded

Solutions

  • Optimise workpiece and tool clamping
  • Reduce feed rate
  • Change tool earlier

Cratering

Causes

  • Cutting speed to low
  • Insufficient cooling

Solutions

  • An increase in the cutting speed
  • Increase coolant pressure

Point angle fragmentation

Causes

  • Feed rate too low
  • Drill not running true

Solutions

  • Increase feed rate
  • Runout < 0.02 mm

Excessive flank wear on the cutting edge corner

Causes

  • 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

Causes

  • 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