| 摘要 |
<p>[Problem] To provide a self-tapping screw ideal for fastening work made of a soft material such as a resin or aluminum alloy. [Solution] A self-tapping screw (1): that is equipped with normal screw crests (10) and a female thread-forming screw crest (12) having a larger diameter than the normal screw crests (10); and in which one of the pitches between said normal screw crests (10) that are located on the head-ward side of the female thread-forming screw crest (12) is set to be larger than the other pitches. The self-tapping screw (1) provides a reduction in screwing torque together with an improvement of fastening strength, and can be used for various kinds of workpieces, from soft materials to hard materials.</p> |
