| 摘要 |
PURPOSE: To finish an inner circumferential surface of a hole circular in section in a short time. CONSTITUTION: A cylindrical part 23 is provided on a forward end part of a shank part 21 through arm parts 22, 22. A slit 24 extending from one end to the other is formed in the cylindrical part 23. The cylindrical part 23 can be expanded/contracted thereby. A projected bar 25 whose diameter is slightly larger than that of the inner circumferential surface of a hole to be finished is formed on the outer circumferential surface of the cylindrical part 23. |
