| 摘要 |
PROBLEM TO BE SOLVED: To enable grinding by stages such as rough cutting, finishing and so on without replacement by another file by providing a file with grinding surfaces different in filing size. SOLUTION: A file 1 mounted on a driver making a rotary motion through a rotating shaft 2 is formed like a disc having a smooth cut tip surface 4 and a bastard cut peripheral side surface 5. The bastard cut peripheral side surface 5 has high rotating speed and a bastard cut file to be used in the rough cutting stage. At the finish stage, shaping or polishing is performed by a smooth cut file of the smooth cut tip surface 4. Thus, one file body 1 is provided with grinding surfaces different in filing size, whereby grinding by stages such as rough cutting, finishing and so on can be performed without replacement by anther file. Since a bastard cut file having a large grinding amount per unit hour is arranged in the high speed rotating grinding surface of the file 1, grinding can be performed efficiently. |
