| 摘要 |
As viewed in a direction perpendicular to the line connecting noses (L), each cutting edge (5) forms a convex curve with its nose portion (2) at the lowest level. As viewed in a direction perpendicular to the abovesaid direction, rake faces (1-1, 1-2) form symmetrical, downwardly sloping convex accurate surfaces or straight surfaces having a positive rake angle ( alpha ) of 5-25 DEG . The wedge angle ( beta ) at the cutting edges is set at 85-65 DEG . Thus, the rake angle will be negative at the noses and positive at other portions. Further, the rake angle increases toward the side where the cutting speed is higher. The thickness of the insert increases toward the side where the load is greater. <IMAGE> |
