| 摘要 |
The fastening element (10) has a first (12) and a second bolt portion 30) separated by a thin integral flange (18). The first portion is provided with self-tapping external thread (16, 14). On the side of the portion (30), the flange face has an upward projection (24). The upward projections extend in radial direction and are contoured so that one radially extending side (26) is at right angles to the flange face, whilst the other side (28) slopes upwards from the face to meet the side (26). A suitable tool can engage the sides and transmit a torque to the bolt so as to screw the portion into a bore. |
