Schneideinsatz

摘要

The invention relates to a cutting insert. The cutting insert has a polygonal tabular body having a main cutting edge and a sub-cutting edge. A rake surface connected to the main cutting edge and the sub-cutting edge is composed of a plurality of consecutive component surfaces so as to present a multi-face surface which is curved and convex along the circumference of the body. The consecutive component surfaces are demarcated from adjacent component surfaces by edges lines L1, L2 which at their one end reach the main cutting edge. The intersection angles at which the component surfaces intersect the end surface connected to the main cutting edge are so varied in a stepped manner that the intersection angle of the component surface most remote from the nose portion is the smallest. The third component surface is curved along the circumference of the body so as to be convex outward, so that the portion of the main cutting edge associated with this component surface is also curved to be convex outward.