Patent ID: 9297403
Filing Date: 2016-03-29
CPC Classification: F16B

Claim Text:
1. A self-tapping screw with a head and an outer thread support, wherein a core cross section of the outer thread support has the shape of a rounded n-sided polygon, wherein n is 5 or 7, and the shape of the rounded n-sided polygon is formed from 2 times n curved portions with a large radius R and a small radius r in alternation, n-centers of the radii R, r being positioned at equal distances from one another on an auxiliary circle which is arranged coaxially inside the core cross section and has a radius φ, and each center being associated with a closest curved portion with a small radius r and with an opposite curved portion with a large radius R on the auxiliary circle above the center, wherein the dimensions of the core cross section of the outer thread support are determined as follows, k being a desired unroundness, subject to a material, of the thread cross section, C being an enveloping circle diameter and D a thread internal diameter: