| 摘要 |
PURPOSE: To provide throw away tips and a ball end mill capable of evenly distributing forces applied to tips, and efficiently removing chips. CONSTITUTION: A triangular tip 13 is arranged in close proximity to the center on the cutting end face of a ball end mill, and substantially rectangular first rectangular tips 16, 19 are arranged on the radial surface. Further, second rectangular tips 15, 17 are arranged axially behind the triangular tip 13 and axially ahead of the first rectangular tips 16, 19. Third rectangular tips 14, 18 are arranged axially behind the first rectangular tips 16, 19. The triangular tip 13 is provided with three main cutting edges 23, 24, 25 which are straight when viewed from above. A second cutting edge 26 of radius R is formed on a corner of the triangular tip 13. The second cutting edge 26 has one main cutting edge 23 as its tangent, and intersects the other main cutting edge 25 at a point 27 at an angle of obtuse angle. |
