Patent ID: 7175370

Claim:
An indexible cutting bit for turning, comprising a body having an upper side of polygonal contour, a lower side oriented generally parallel to the upper side, at least three peripheral faces interconnecting the upper and lower sides, wherein intersections between the upper side and the peripheral faces, respectively, define main cutting edges; and minor cutting edges; wherein the polygonal contour is defined by an at least triangular shape which has cut-off corner regions, wherein the main cutting edges are defined by the side faces of the polygonal contour and the minor cutting edges are defined by the cut-off corner regions; the minor cutting edge comprising: a convexly curved transition first portion extending from an end of a first main cutting edge: a concavely curved second portion, a convexly curved, intermediate third portion, a concavely curved fourth portion, a convexly curved, intermediate fifth portion, a concavely curved sixth portion, and a convexly curved transition seventh portion extending to a second main cutting edge; wherein each of the first, third, fifth, and seventh portions is defined by a radius of curvature, wherein the convexly curved, intermediate third portion and the convexly curved, intermediate fifth portion have different radii of curvature, one of said radii being substantially larger than the other and larger than the radius of the convexly curved transition first and seventh portions.