| 摘要 |
<p>A ball end mill enabling an increase in machining efficiency, wherein a pair of roughly semi-spherical ball edges (12a) and (12b) are formed on an edge part (3) at the tip thereof symmetrically with respect to the axis thereof, and the area of the edge part (3) including at least the ball edges (12a) and (12b) is formed of a hard sintered body (PCBN). Also, the faces of the ball edges (12a) and (12b) are formed by spiral gashes (14a) and (14b), and the helix angles of the spiral gashes (14a) and (14b) are formed at approximately 20˚. Since the ball edges (12a) and (12b) are formed of the hard sintered body having high hardness characteristic and formed in a twisted shape, the ball end mill can cut with a large depth of cut and at high speeds to increase the machining efficiency of the ball end mill.</p> |
