| 摘要 |
A cutting insert which improves chip processing performance at the time of cutting processing and defect resistance performance is provided. In a cutting insert having an approximately polygonal plate shape, in which a cutting edge (6) is formed on a intersection portion between a rake face (2a) and a flank (4a) , and a chip breaker (20) is formed on the rake face (2a), a chip-breaker concave portion (40) is defined by an inclined surface (40b) which is curved in a concave manner and which is smoothly connected to the bottom surface portion (40c) while being gradually inclined toward the bottom surface portion (40c), from a peripheral edge portion on a nose portion (5) side to a bottom surface portion (40c). |
