Abstract: A side cutter has a substantially disk-shaped or substantially ring-shaped cutter body, two or more peripheral cutting inserts each having a cutting edge protruding from a peripheral surface of the cutter body, and two or more corner cutting inserts each having a cutting edge protruding from an end surface of the cutter body. The peripheral cutting insert and the corner cutting insert are arranged in the cutter body such that the cutting edges adjacent to each other in the circumferential direction have overlapping rotational trajectories around the axis of rotation of the cutter body. In addition, a peripheral cutting insert and a corner cutting insert belonging to an insert set are spaced from each other in an axial direction of the cutter body and are arranged substantially in the same position in the circumferential direction of the cutter body.

Abstract: An insert has a lower face formed in a substantially quadrangular shape, a flank formed on an upper face formed in a convex face rising upward from two opposing sides of the quadrangular face, a pair of rake faces rising upward from the other two opposing sides of the quadrangular face and formed in first side faces intersecting with the convex curved face, a pair of corner edges formed respectively in ridgeline portions between the rake face and the flank, and a pair of second side faces which intersect obliquely to the two opposing sides of the quadrangular face and rise upward from the lower face to notch an intersection portion between the lower face and the upper face.