Patent ID: 7021877

Claim:
Self-tapping screw ( 1 ) comprising a head and a core, the core having a front area, a rear area and a transition between the rear area and the front area, with threads in the rear area ( 5 ) having a substantially cylindrical external diameter and in the front area ( 4 ) extending with an external diameter which decreases from the transition toward a leading end of the screw, the threads having a load flank ( 12 ) and a rear flank ( 11 ) which define a flank angle (γ), characterized in that, the threads of the screw in the rear area ( 5 ) have a straight load flank ( 12 ) from a tip ( 13 ) of the threads to the core ( 14 ), and in the front area ( 4 ) a straight rear flank ( 11 ) from the tip ( 13 ) to the core ( 14 ), the threads forming a generally triangularly cross section with an oblique bisector ( 9 ) of the flank angle (γ) directed outwardly between the load flank ( 12 ) and the rear flank ( 11 ), the bisector reversing from the rear area ( 5 ) to the front area ( 4 ) such that the bisector is outwardly inclined away from the screw head ( 2 ) in the rear area ( 5 ) and outwardly inclined toward the screw head ( 2 ) in the front area ( 4 ); and wherein in the front area ( 4 ), the load flank ( 12 ) runs from the external diameter to the core ( 14 ) over a bend ( 15 ) to a greater flank angle (δ).