| 摘要 |
A cutting tool includes a working portion adapted to cut a threaded hole or a hole in a predetermined workpiece, a first clamp portion provided at an end opposite to the working portion and adapted to be clamped by a clamping device to facilitate local application of force, and a weak portion disposed between the working portion and the first clamp portion and adapted to bear a torsional force smaller than that borne by other portions. The weak portion, during use of the cutting tool in a cutting operation, is always located on the surface of the workpiece and will break when the cutting tool cannot stand an excessive torsion. The broken portion will likewise always be located on the surface of the workpiece, whereby the user can easily clamp the portion exposed on the outside of the workpiece. |
