| 摘要 |
<p>The invention relates to a screw (1) having a threaded shank (2) and a screw tip (6). The threaded shank (2) is composed of a shank core (10) and a thread which extends helically over the shank core (10). Two flanks (15, 16) which converge in an outer thread edge (14) has a height (H) measured radially from the shank core (10) to the thread edge (14). The thread (12) has a specific apex angle (α) formed between the adjacent flanks (15, 16). Preferably the outer thread edge (14) extends in a wave form in the radial direction with an amplitude (U) between wave crests (20) forming indentations (24) which interrupt the surface of the flank (15/16). At least one of the two flanks (15, 16) of the thread (12) is formed concavely in the region between the shank core (10) and the thread edge (14), seen in radial profile, in such a way that the apex angle (α) is less than a flank angle (αF). With preference, the thread (12) respectively has in the regions that are not interrupted by indentations (24).</p> |
