| 摘要 |
The radius end mill includes: an end mill body which is rotatable around an axis; peripheral cutting edges each formed at a peripheral portion of the end mill body located close to a distal end thereof; bottom cutting edges each formed at a distal end surface of the end mill body; and corner cutting edges each formed between the peripheral cutting edge and the bottom cutting edge. Each of the corner cutting edge is formed so as to curve inwardly in a radial direction of the end mill body as the corner cutting edge approaches the distal end of the end mill body from the terminal end thereof and so as to curve toward the terminal end of the end mill body after the corner cutting edge has reached the distal end of the end mill body. Each of the bottom cutting edge is formed so as to communicate with the corner cutting edge and so as to be close to the terminal end of the end mill body as the bottom cutting edge approaches inwardly in the radial direction. A value of a rake angle ± of the corner cutting edge with respect to the axis is greater than or equal to -10° and is less than or equal to 10°. A rake surface of the corner cutting edge and a rake surface of the bottom cutting edge each are formed like a plane, and the rake surface of the corner cutting edge is formed so as to be flush with the rake surface of the bottom cutting edge. When an external diameter of the end mill body is D, a value of a curvature radius R of the corner cutting edge is greater than or equal to 0.1 x D and is less than or equal to 0.3 x D. |
