| 摘要 |
<p>A chuck for driving drill bits an the like having shafts of hardened steel is provided with clamping jaws which at least at their clamping surfaces have a coating of diamond dust, so that they will have a resistance to abrasion that is greater than that of hardened steel. The diamond dust can embed itself in the clamping jaws. The entire chuck jaw may be made with a material having that property or one or more clamping parts of the jaw may be made of such a material, or the coating may be provided on a part of the chuck jaw or on the clamping parts.</p> |
