Patent ID: 6722833
Filing Date: 2004-04-20
Classification: F16B

Abstract:
A self-tapping screw having a screw head and a screw tip defining a longitudinal screw axis, said screw including a plurality of rolled thread turns extending along said screw axis defining a thread pitch between adjacent ones of said turns, an angle bisector of each turn sloping away from said screw head at a perpendicular to said screw axis, each turn comprising:a thread root defining a core diameter; a thread tip defining an outside diameter; a load flank; and a rear flank which slopes away from said screw head at an angle &dgr; with respect to the perpendicular to said screw axis, said angle &dgr; being between 30Â° and 50Â°; wherein said load flank runs in a straight line to said threat root and defines an angle &ggr; with respect to the perpendicular of said screw axis, and said rear flank extends in a first straight line portion from said thread tip and at approximately &frac13; of its height merges via a kink into a second straight line portion angled relative to said first straight line portion at an angle &agr;, angle &agr; being greater than angle &dgr;, the ratio of said core diameter to said outside diameter being greater than 0.7, and the ratio of said threat pitch to said outside diameter being less than 0.25.