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TOOL WEAR AND DAMAGE

CAUSES AND COUNTERMEASURES

Tool damages from		Cause	Countermeasure
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		-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		-Tool grade is too hard. -Feed rate is too high. -Lack of cutting edge strength. -Lack of shank,holder rigidity.	-Tool grade with high toughness. -Lower feed rate. -Increase honing.(Round honing is to be changed to chamfer honing) -Use larger shanksize.
Fracture		-Tool grade is too hard. -Feed rate is too high. -Lack of cutting edge strength. -Lack of shank,holder rigidity.	-Tool grade with high toughness. -Lower feed rate. -Increase honing.(Round honing is to be changed to chamfer honing) -Use larger shank size.
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		-Cutting speed is low. -Poor sharpness. -Unsuitable grade.	-Increase cutting speed (For ANSI1045,Cutting speed 260SFPM)) -Increase rake angle. -Tool grade with low affinity (Coated grade,cermet grade)
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		-Hard surfaces such as uncut surface chilled parts,and machining hardened layer. -Friction caused by jagged shape chips. (Caused by small vibrations)	-Tool grade with high wear resistance. -Increase rake angle to improve sharpness.
Flaking		-Cutting edge welding and adhesion. -Poor chip disposal.	-Increase rake angle to improve sharpness. -Enlarge chip pocket.
Flank Wear Fracture *Damage for polycrystallines		-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		-Tool grade is too soft -Cutting resistance is high and cutting heat generation is high	-Decrease honing. -Tool grade with high wear resistance.