摘要 |
Self-boring screw comprises a first cutting edge (21) arranged in a radial inner region of the tip (12). An enveloping cone casing surface (A1) defined by the first cutting edge corresponds to a maximum deviation of + or - 10% of an enveloping cone casing surface (A2) defined by a second cutting edge (22). A first acute angle of the first cutting edge towards the longitudinal axis (L) with a maximum deviation of + or - 5% corresponds to a second acute angle to the second cutting edge towards the longitudinal axis. Preferred Features: The first cutting edge extends from an axial region close to the longitudinal axis to a first radius. The second cutting edge extends from an outer radius of the tip towards the longitudinal axis up to a second radius. |