| 摘要 |
<p>The insert (1) has a torsion shaft (6) arranged between a drive end (2) and a screwdriver end (4). A spiral drill zone is provided at the torsion shaft and formed around the torsion shaft in longitudinal direction (7) and circumferential direction (8), where the torsion shaft is placed outside the zone. The zone runs out with respect to a longitudinal axis (16) of the torsion shaft in normal levels (10). The zone has a recess (11) whose depth (12) decreases towards the screwdriver end.</p> |
