Screw for fastening wood panel in porous concrete, has screw threads sweep in region of drive end of screw shaft with screw head, where external diameter of screw head is greater than external diameter of one of screw threads

摘要

The screw has a set of screw threads (7, 8) sweep in a region of a drive end (3) of a screw shaft (1) with a screw head (4). External diameter of the head is greater than 1.5 times of external diameter of one of the screw threads. The shaft includes a holding section (6) with the screw threads, where the holding section is provided from the drive end. A thread-free screw section (9) is provided adjacent to the holding section and a front screw-in section with another set of screw threads and a front screw end, where a pitch of the screw threads is identical to the screw section.