Composite screw

Claim 1

A fastener unit including a one-piece metal body with a composite plastic head portion, the metal body including a small cylindrical head portion being continuous throughout the periphery thereof a threaded shank portion and a load bearing and torque transmitting flange portion having an upper and lower surface, said flange extending radially outwardly from the head portion, and said threaded shank portion extending downwardly from the flange, the cylindrical head portion of the metal body having a diameter generally corresponding to the diameter of the threaded shank portion and including a plurality of external torque transmitting vertical splines, the flange portion of the metal body including a plurality of radially directed axial projections on at lease one substantially radially extending surface thereof, a plastic member molded over and encapsulating the head and covering both the upper and lower surface of the flange member of the metal body and forming external head and flange portions corresponding to the head and flange of the metal body, the outer diameter of the external head portion being less than the outer diameter of the flange portion of the metal body, said vertical splines interlocking with the external head portion and the axial projections interlocking with the external flange portion of the molded plastic member to prevent relative rotation between the plastic member and the metal body as well as precluding relative axial movement between the metal head and the plastic head portion, the axial projections also providing means for effectively increasing the torque accepting diameter of the relatively small head on the metal body, the external head portion including a plurality of tool engaging projections.