Assembly screw for butt or mitre jointed wooden section members

摘要

The screw has two shank sections, with the larger diameter section(2) threaded(A) over only one part of its axial length facing the tool attachment end. The portion(C) of the shank section joining the threaded portion is plain up to the transition to the smaller diameter shank section(9). The threaded portions(A,B) of the screw have the same or different thread pitch(S). The plain portion(C) of the screw has a diameter corresponding to, or smaller than, the core diameter of the portion(A) formed by the thread.