Trouble shooting Cutting edges figuration and countermeasures Typical cutting edge figuration Observation Causes Countermeasures • Deterioration of surface roughness • Too high Vc • Reduce Vc and dimensional accuracy • End of tool life • Change to higher wear resistant grade Nose wear • Burr formation • Too high f and Vc • Sharper cutting performance • Cutting force increase • Reduce Vc Notching • Change to higher heat resistant grade • Chip control deterioration • Too high Vc • Reduce Vc • Surface finish deterioration • Change to high speed type like Cermet or Crater wear (peeled surface) Al2O3 coated insert grade • Workpiece dimension changes • Too high cutting load • Change to harder grade • Crack at nose • Inappropriate insert grade • Reduce f and ap Plastic deformation • Surface finish's sudden • Too high Vc • Change the tool earlier deterioration • Change to higher wear resistant grade Crack from wear • Workpiece dimension changes • Cutting force increase • Too high f • Reduce f and ap • Surface roughness deterioration • Chattering • Change to more rigid toolholder Chipping • Lack of insert toughness • Change to tougher grade R • Surface finish deterioration • Too low Vc • Increase Vc Crack from welding • Cutting force increase • Improve sharp cutting performance (rake or built-up edge angle, chamfer) • Sudden cracking • Too high f and ap • Change to tougher grade • Unstable tool life • Chattering • Enlarge chamfer Mechanical fracture • Enlarge Corner-R(RE) • Change to more rigid toolholder • Cracking by heat cycle • Too high Vc and f • Reduce f Fracture from • Possible in interrupted machining • Reduce Vc thermal crack and milling • Change to dry cutting • Possible in hard materials • Lack of insert toughness • Change to tougher grade machining • Poor rigidity of toolholder (TiC-base ceramic to CBN.) Flaking • Possible in machining with • Change to more rigid toolholder chattering • Change edge preparation R36 Technical information