Normal drill wear

Under ideal conditions, uniform wear should be seen along the entire cutting edge.

  • Cutting speed OK
  • Feed rate OK
  • Drill and workpiece are clamped correctly

Maximum wear prior to regrinding

Drilling tools should be reground when the wear land has grown to a specific width (VB) along with a certain amount of cratering (KB). 

  1. Rake surface
  2. Circular land
  3. Flank
  4. Area
  5. Drill centre
Maximum flank wear (VB) in mm
  Area
Drill diameter in mm  3 2 1
3.00 – 6.00 0.20 0.20 0.20
6.01 – 10.00 0.25 0.20 0.20
10.01 – 14.00 0.25 0.25 0.25
14.01 – 17.00 0.30 0.25 0.25
17.01 – 20.00 0.35 0.30 0.30
Crater wear (KB) in mm
  Area
Drill diameter in mm  3 2 1
3.00 – 6.00 0.20 0.20 0.20
6.01 – 10.00 0.25 0.25 0.25
10.01 – 14.00 0.30 0.30 0.30
14.01 – 17.00 0.30 0.30 0.30
17.01 – 20.00 0.35 0.30 0.30