| 摘要 |
<p>1. Stud made of hard material for a drilling tool, consisting of a head (6) prolonged by a body (7) intended to be set into the end of the tool in a chamber (4) having dimensions slightly less than those of the body (7), in which stud the outer surface of the body (7) has teeth (8) intended to penetrate the inner wall of the chamber (4) when the stud (5) is set into the chamber (4), characterised in that the teeth (8) are arranged along helices marked on the surface of the body (7).</p> |
