Patent ID: 6361259
Filing Date: 2002-03-26
Classification: F16B

Abstract:
A screw adapted for torque-limited fastening of metal or plastic sections or plates to a substructure, comprising a shank with a boring portion having a boring diameter, a threaded portion, an unthreaded portion having a diameter which is less than an outer diameter of the threaded portion, and a drive portion adapted for applying a driving tool and having an underside which is generally perpendicular to the screw axis, the shank further comprising a portion adjacent to the drive portion that flares conically from the unthreaded portion toward the drive portion underside and having a diameter at the end of the conical portion of the shank close to the drive portion underside that is larger than the diameter of a borehole adapted to be formed by the boring portion which receives the screw in a section to be fastened and thus is also larger than the boring diameter of the boring portion, wherein the diameter at the end of the conical portion of the shank close to the drive portion underside is also larger than the outer diameter of the threaded portion and wherein as a result of an axial force generated by screwing the screw into a substructure, the conical portion is pulled into the borehole accommodating the screw and at the same time causes a torque increase to prevent stripping of the threaded portion in the substructure.