| 摘要 |
PURPOSE:To increase the brazing strength and permit the deflection of the starting edge in the axial direction of the outer peripheral cutting edge of an outside tip by installing an engaging stepped part at the edge-surface connection part between a top stage tip and a tool body. CONSTITUTION:A top edge tip 2 and outside tips 3 and 4 are brazed onto the top edge and the side parts of a cylindrical tool body, and an engaging stepped part 7 is formed onto the connection part with the body 1 of the tip 2. An amount delta of deflection is formed at the starting edge in the axial direction of an outer peripheral cutting edge 8 because of the existence of the stepped part 7. The brazing strength can be increased by reducig the ratio L2/D between the cutting-edge diameter D of the tip 2 and the length in the axial direction, besides the existence of the stepped part 7. |
