| 摘要 |
A power tap structure comprises a screw head, a bolt being a rod body extended underneath the screw head, and at least two screw thread units having different cutting surfaces respectively called a cutting thread and a retaining thread. Each of the crew thread units further includes a plurality of thread sections connected by a transition screw thread. The cutting thread has a plurality of indentations distributed along a cutting thread surface thereon, whereby the indentations on the cutting thread will effectively cut fibers of a material the bolt is being inserted. Therefore, the screw will penetrate the material quickly and easily. Further, an additional thread unit with narrower pitch can be formed right below the screw head for enhancing the locking effect of the screw when it is embedded into the material. |
