Patent ID: 11554428

Abstract:
A cutting insert suitable for a small-diameter milling tool is provided. A cutting insert has a rake face, a bottom surface, a circumferential side surface, and a through hole. A first ridgeline at which the rake face and the circumferential side surface intersect each other includes a first main cutting edge, and a first corner cutting edge connected to a tip of the first main cutting edge. The bottom surface includes a first bottom surface that comes closer to the rake face gradually toward a side at which the first main cutting edge is located when viewed from a central axis of the through hole, and a second bottom surface that comes closer to the rake face gradually toward a side opposite to the first main cutting edge when viewed from the central axis. A distance between a virtual intersection line, at which a first virtual surface formed by extending the first bottom surface and a second virtual surface formed by extending the second bottom surface intersect each other, and the first main cutting edge decreases from a tip side, at which the tip of the first main cutting edge is located, toward an end side, at which an end opposite to the tip is located, in an extending direction of the first main cutting edge.