Screw for screwing into a material of low hardness, e.g. hard plastics

摘要

The flank height (H) and the core diameter (Dk) of the thread form the ratio Q1=H/Dk in the range of 1 to 3.5, preferably 2. The core diameter (Dk) and the thread pitch (P) form the ratio Q2 = Dk/p in the range of 0.3 and 0.6, preferably 0.5. The thread is formed as angular thread with a crown angle of thread teeth less than 30 degrees.