| 摘要 |
A cutting insert capable of designing an optimal shape for each of a chip breaker for a cutting edge used for cutting of an outermost region of a hole is provided. A substantially polygonal upper face (2), a substantially polygonal lower face (3), and a plurality of side faces (4m, 4s) extending between the upper face (2) and the lower face (3) are provided, wherein the plurality of side faces (4m, 4s) include a main side face (4m) constituting a flank of a linear cutting edge (5b) and a sub side face (4s) constituting a flank of a corner cutting edge (5a), the main side face (4m) has a relief angle of 0°, the sub side face (4s) has a relief angle larger than 0°, and a second cutting edge (8) is further provided at an intersection portion between the main side face (4m) and the lower face (3). |
