CUTTING INSERT AND REPLACEABLE TOOL EDGE ROTARY CUTTING TOOL

摘要

In this cutting insert, the cutting edge is provided with: a first corner edge; a linear main cutting edge extending from the end (S1) of said first corner edge that is toward the short side surface; a circular arc-shaped first auxiliary cutting edge extending from the other end (S2) of the main cutting edge; and a linear second auxiliary cutting edge extending from the other end (S3) of the first auxiliary cutting edge. In a rake face cross-sectional view that is perpendicular to the second auxiliary cutting edge, the rake face cross-section ridge of the second auxiliary cutting edge is formed so as to have a protruding shape that protrudes upward with respect to the cross-section ridge of a flat reference surface.