摘要 |
PROBLEM TO BE SOLVED: To provide a broach tool capable of improving a tool life by abrasion or chipping and process tolerance of a workpiece, and suppressing cost furthermore than hitherto.SOLUTION: A broach tool has many cutting edges in which the edge height becomes higher gradually in the order of a rough edge group, a semi-finishing edge group, and a finishing edge group at least in the longitudinal direction. In the broach tool, the film thickness of a hard film with which each cutting edge is coated is reduced gradually in the order of the rough edge group, the semi-finishing edge group, and the finishing edge group. |