| 摘要 |
A cutting insert (1) according to an embodiment of the present invention has a cutting edge having a first corner cutting edge (5a), a flat cutting edge (6), a connecting edge (8), a major cutting edge (7), and a second corner cutting edge (5b) in the order named. The major cutting edge (7) has an upwardly protruding curvilinear portion (71), a first straight line portion (72) extending from the curvilinear portion (71) toward the connecting edge (8), and a second straight line portion (73) extending from the curvilinear portion (71) toward the second corner cutting edge (5b). The flat cutting edge (6) and the major cutting edge (7) have a straight line shape, and the connecting edge (8) has an outwardly protruding curvilinear shape in a top view. The flat cutting edge (6), the connecting edge (8), and the first straight line portion (72) are located on a straight line in a side view. |
