| 摘要 |
<p>The self-tapping screw (1) has a threaded shaft (1.1) and a screw tip (1.2) at the end of shaft. A screw thread (2) has tapping threaded portion (4) and basic threaded portion (3). The increase of the effective diameter and/or the outer diameter over length of the basic threaded section lengthening towards screw tip, lies in a ratio from 1:50 to 1:500, preferably in ratio from 1:100 to 1:400. The increase of effective diameter and/or outer diameter over basic region remains constant, so that basic threaded section from the screw tip is conic extended. An independent claim is included for blank for producing self-tapping screw.</p> |
