| 摘要 |
PURPOSE:To stabilize the tolerances of a machined hole by replaceably attaching one or more cutting edge tips to the end part of a tool main body by using clamping means and providing the peripheral end part of each cutting edge tip with a convex part corresponding to a margin part and a flank. CONSTITUTION:Cutting edge tips 11 and 11 are replaceably attached to a drill main body 10 by using screws 12 and 12. The peripheral end part 13 of each tip 11 is formed into a columnar convex. When each cutting edge tip 11 is mounted on a tip seat 15, the convex surface of the tip 11 is simultaneously provided with a part 16 corresponding to a margin capable of obtaining a margin effect and a minor flank 17 corresponding to a peripheral flank. Accordingly, the cutting edge tip 11 can obtain a working effect as a margin. |
