MITSUBISHI MATERIALS CORPORATION
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TOOL WEAR AND DAMAGE

CAUSES AND COUNTERMEASURES
Tool damages from Cause Countermeasure
Flank Wear Flank wear
  • Tool grade is too soft.
  • Cutting speed is too high.
  • Flank angle is too small.
  • Feed rate is extremely low.
  • Tool grade with high wear resistance.
  • Lower cutting speed.
  • Increase flank angle.
  • Increase feed rate.
Crater Wear Crater wear
  • Tool grade is too soft.
  • Cutting speed is too high.
  • Feed rate is too high.
  • Tool grade with high wear resistance.
  • Lower cutting speed.
  • Lower feed rate.
Chipping Chipping
  • Tool grade is too hard.
  • Feed rate is too high.
  • Lack of cutting edge strength.

  • Lack of shank or holder rigidity.
  • Tool grade with high toughness.
  • Lower feed rate.
  • Increase honing. (Round honing is to be changed to chamfer honing.)
  • Use large shank size.
Fracture Fracturing
  • Tool grade is too hard.
  • Feed rate is too high.
  • Lack of cutting edge strength.
  • Lack of shank or holder rigidity.
  • Tool grade with high toughness.
  • Lower feed rate.
  • Increase honing. (Round honing is to be changed to chamfer honing.)
  • Use large shank size.
Plastic Deformation Plastic deformation
  • Tool grade is too soft.
  • Cutting speed is too high.
  • Depth of cut and feed rate are too large.
  • Cutting temperature is high.
  • Tool grade with high wear resistance.
  • Lower cutting speed.
  • Decrease depth of cut and feed rate.
  • Tool grade with high thermal conductivity.
Welding Welding
  • Cutting speed is low.

  • Poor sharpness.
  • Unsuitable grade.
  • Increase cutting speed. (For ANSI 1045, cutting speed 260 SFM.)
  • Increase rake angle.
  • Tool grade with low affinity. (Coated grade, cermet grade)
Thermal Cracking Thermal cracking
  • Expansion or shrinkage due to cutting heat.

  • Tool grade is too hard.
  • *Especially in milling.
  • Dry cutting. (For wet cutting, flood workpiece with cutting fluid)
  • Tool grade with high toughness.
Notching Notching
  • Hard surfaces such as uncut surface, chilled parts and machining hardened layer.
  • Friction caused by jagged shape chips. (Caused by small vibration)
  • Tool grade with high wear resistance.

  • Increase rake angle to improve sharpness.
Flaking Flaking
  • Cutting edge welding and adhesion.
  • Poor chip disposal.
  • Increase rake angle to improve sharpness.
  • Enlarge chip pocket.
Flank Wear Fracture
*Damage for
polycrystallines		 Flank wear fracture
  • Damage due to the lack of strength of a curved cutting edge.
  • Increase honing.
  • Tool grade with high toughness.
Crater Wear Fracture
*Damage for
polycrystallines		 Crater wear fracture
  • Tool grade is too soft.
  • Cutting resistance is too high and causes high cutting heat.
  • Decrease honing.
  • Tool grade with high wear resistance.