US Patent 10112241 Insert, tool holder, and assembly thereof

A technical object of the present disclosure is to provide an insert, which can maintain rigidity thereof regardless of a clearance angle of a clearance surface that forms a circular cutting edge. To this end, the insert according to the present disclosure includes a circular upper surface, a circular lower surface, and a clearance surface portion connecting the upper surface and the lower surface. The clearance surface portion is divided into first and second clearance surfaces along a circumference thereof, by a first wave line that forms a waveform of valleys facing the lower surface and mounts facing the upper surface.