| 摘要 |
PURPOSE:To aim at enhanced accuracy of machining by means of improved centripedalism of a tool by setting up a relief surface with two steps consisting of the first and second relief surfaces, and forming a band-shaped stand surface on the face extending from the second relief surface. CONSTITUTION:Respective pairs of front cutting edge 5, relief surface 6 and thinning 7 are formed on the tip area of a tool made of sintered hard alloy. The relief surface 6 is set up in two steps consisting of the first relief surface 6a and second relief surface 6b, particularly for the purpose of enhancing its centripetalism. A band-shaped slant surface 9 is in flat with the relief surface 6b and is a result of 'so-called' chamfer to be positioned on its extending face. Provision of such slant surface 9 can enhance the centripetalism of a tool, duly improving the accuracy of machining. |
