Patent ID: 9393626
Filing Date: 2016-07-19
CPC Classification: B23B,Y10T

Claim Text:
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-shaped in which a cutting edge is formed at an intersection of the upper surface and the side surface, wherein the upper surface comprises a convex-shaped main part comprising a flat upper end surface, a first projection projecting from the main part to a corner part of the upper surface in a top plan view, a second projection projecting from the first projection toward the corner part in the top plan view, and a pair of third projections respectively projecting from the first projection toward a periphery of the upper surface so as to interpose at least a part of the second projection between the pair of third projections in the top plan view, wherein a surface of the first projection is an inclined surface curved in a concave shape, and a surface of the second projection is a planar inclined surface in a portion located on a bisector of the corner part in the top plan view, wherein a width of the inclined surface curved in the concave shape of the first projection in a direction orthogonal to a direction in which the first projection projects is gradually decreased from a rear end of the inclined surface to a front end thereof in the top plan view, and wherein a width of the planar inclined surface of the second projection in a direction orthogonal to a direction in which the second projection projects is gradually increased from a rear end of the inclined surface to a front end thereof in the top plan view.