| 摘要 |
<p>The part has a retaining head (4) integrated to a tubular mast (5), and with a pointed shaped end (6) having a bore constriction, where diameter of the constriction lower than that of a head of a screw forms a chamfer. The constriction has an axial orifice (8) by which the screw partially exits. The mast has, on an exterior wall of the mast, a main projecting rib (13a) extending from the retaining head until the end, where the end is sharpened in the form of a bevel. A beveled surface (16) e.g. concave surface, of the end is encircled by two stops (17a, 17b) converging towards the end.</p> |
