| 摘要 |
<p>One aspect of the present invention provides a cutting insert (10) having a plurality of cutting portions (18) which are formed at the intersections between each edge (12, 14) and a peripheral face (16). Each cutting portion includes a first cutting edge (18a) and a second cutting edge (18b). In an end view, each edge is provided alternately with a first corner (20) and a second corner (22) which have different interior angles. The interior angle (a) of the first corner (20) is less than the interior angle (ß) of the second corner (22, 122, 222). Each first cutting edge (18a) has a portion which extends so as to approach a center plane (M) with increasing distance from the corresponding first corner (20). A first side portion (30a) extending from each first cutting edge to the peripheral face forms an insert interior obtuse angle with respect to a plane parallel to the center plane (M) passing through the first cutting edge, while a second side portion (30b) extending from each second cutting edge to the peripheral face forms an insert interior acute angle with respect to a plane parallel to the center plane (M) passing through the second cutting edge.</p> |
