| 摘要 |
PROBLEM TO BE SOLVED: To provide a throwaway tip that is reduced in cutting resistance and improved in cutting performance without an influence on the polishing accuracy of its mounting face. SOLUTION: The throwaway tip has a practically polygonal plate shape, and one surface opposite to a mounting face 20 to a tool body is a rake face 10. The rake face 10 has a nose portion 40 having a practically arc cutting edge at each corner portion 30, and a main cutting edge 60 along the ridge where a side face 50 adjoining the nose portion 40 and the rake face 10 meet. The cutting edge of the nose portion 40 has a flat cutting edge portion 41 practically parallel with the mounting face 20, and an oblique cutting edge portion 42 extending between the flat cutting edge portion 41 and the main cutting edge 60 and having a gradually changed distance from the cutting edge to the mounting face 20.
|
