Kugelkopffräser.

摘要

The invention relates to a ball end mill which has a hemispherical portion (21) formed at a front end of an end mill body (20). A pair of tip mounting seats are formed at the hemispherical portion (21). A main throw-away tip (6) and a second throw-away tip (7) are secured on the tip mounting seat respectively such that the axial rake angle of the main tip (6) is set at a negative angle and the axial rake angle of the second tip (7) is set at a positive angle. A second ball end mill is also disclosed. In this ball end mill, only a main throw-away tip is secured on a tip mounting seat. The axial rake angle of the main tip is set at a negative angle. One or more chip breaker grooves are formed on a rake face of the tip.