摘要 |
The present invention enhances the lubricating property of the sliding surfaces of a clamp nut (30) and a collet (100), reduces a friction coefficient, prevents the occurrence of seizure, and enhances durability. Accordingly, it is possible to rotate the clamp nut and the collet without causing vibrations due to imbalance. Moreover, this invention provides a clamp nut that can maintain tool-mounting accuracy for a long period of time even in the case of high-speed rotation, and also provides a collet chuck (1) including such clamp nut (32). Concerning the clamp nut which is mounted on a collet chuck body (10) for holding tools in the collet and which clamps the collet chuck body and the collet together, at least a part of the clamp nut which comes in contact with the collet is made of oil-bearing metal. |