Patent ID: 9555489
Date: 2017-01-31
CPC Classifications: B23C,Y10T

Claim:
1. A cutting insert capable of being detachably attached to an insert mounting seat of an indexable cutting tool, the cutting insert comprising: an insert body having a polygonal plate shape, wherein rake faces are formed on polygonal surfaces of the insert body, and flank faces are formed on lateral faces of the insert body arranged around the polygonal surfaces, main cutting edges are formed on side ridges of the polygonal surfaces at intersecting ridgelines between the rake faces and the flank faces, each main cutting edge extends between two corners adjacent to each other in a circumferential direction of the polygonal surface, when seen from a direction opposing the rake face, one end portion of the each main cutting edge that stretches to one corner of the two corners has a convexly curved shape, and the other end portion of the main cutting edge that stretches to the other corner of the two corners has a concavely curved shape, and a clearance angle of the main cutting edge is made larger on a positive angle side at the one end portion of the main cutting edge than at the other end portion of the main cutting edge.