| 摘要 |
PURPOSE:To obtain an almost flat and square thrawaway tip exceedingly suitable for a long, flat drag of a subsidiary cutting edge by providing a notch at the corner of the tip. CONSTITUTION:The subsidiary cutting edge 17 of a flat drag projects 0.05- 0.1mm. to the tip 10 in the direction of the face of a tool body 11 and by a small amount or 0.3-0.5mm. on or inside the same circumference. Thus, the subsidiary cutting edge 17 expresses sufficiently a function as the flat drag for working a finish surface through its comparatively long cutting ridge. The throwaway tip 15 is made nearly rectangular in whole, opposite long side ridges comprise main cutting edges 16, the subsidiary cutting edges 17 are formed on opposite couples of corner parts and notches 18 are provided on the corner parts the other couple. |
