Cutting insert for ball end mill.

摘要

The invention relates to a cutter insert (21) for a ball end mill which includes a plate-like insert body (22), having a front face and a side face extending from said front face. The front face has a generally convexly curved marginal ridge (25) defined by the intersection of the front face with the side face. The marginal ridge (25) serves as a cutting edge (28). The front face serves as a rake surface (23) for the cutting edge (28) while the side face serves as a relief surface (24) for the cutting edge (28). The cutting edge (28) has a leading portion (26) to be indexed in the end cutting position and a trailing portion (27) to be indexed in the peripherial cutting position. A land (30) is formed on the rake surface (23) so as to extend along the cutting edge (28). The land (30) has a width gradually increasing in a direction from the leading portion (26) of the cutting edge (28) toward the trailing portion (27) thereof.