| 摘要 |
The screw (1) has a head (2), and a screw shaft (4) screwed through a fitting assembly into a pre-drilled construction unit. The screw shaft has a cylindrical core (6) and a thread (8) running as a radial bulge in a helix shape. The head has a coil (10) that produces a friction fit in the fitting assembly. The coil is inserted into the fitting assembly and is formed in alignment to a mounting hole. The coil is cylindrically or conical formed, and has axially running ribs (14) radially and symmetrically distributed on a circumference surface (12) of the coil. |
