Patent ID: 9707625
Date: 2017-07-18
CPC Classifications: B23B,Y10T

Claim:
1. A cutting insert, comprising: an upper surface, a lower surface and a side surface located between the upper surface and the lower surface, and a polygonal plate shape in which a cutting edge is formed at an intersecting portion between the upper surface and the side surface, wherein the upper surface comprises a main portion of a convex shape which has a flat upper end surface, a first projecting portion which projects from the main portion to a corner portion of the upper surface, and a pair of second projecting portions which each project from the first projecting portion to a periphery of the upper surface to interpose a region between a front end of the first projecting portion and the corner portion, each of upper ends of the pair of second projecting portions is spaced apart from the first projecting portion, the first projecting portion connects to the main portion and the pair of second projecting portions are apart from the main portion, a rear end of the first projecting portion is closer to the main portion than a rear end of the second projecting portion in a direction of a bisector of the corner portion of the upper surface in a top view, the first projection portion comprises a front end portion interposed between the pair of the second projecting portions and a rear end portion positioned closer to the main portion than the front end portion, a width of the front end portion in a direction orthogonal to a direction in which the first projecting portion projects becomes wider from the rear end to the front end, and a width of the rear end portion in a direction orthogonal to a direction in which the first projecting portion projects becomes narrower from the rear end to the front end.