Patent ID: 7147421
Filing Date: 2006-12-12
Classification: B25B,F16B

Abstract:
1. A screw, comprising: a plurality of recesses for reception of a plurality of bits of a screwdriver, disposed radially about a central axis on a top face of a screw head which is made larger in cross section than a cross section of a screw portion; one of a plurality of engaging walls disposed between two of the plurality of recesses to be engaged with two of the plurality of bits; and one of a plurality of vertical engaging faces disposed on at least one of a plurality of inner walls of one of the plurality of engaging walls and in the proximity of an outer periphery of one of the plurality of recesses, in a fastening direction of the screw; wherein each of the plurality of recesses has tapered overall cross sections with slanted faces tapered downwardly and inwardly along the central axis and each of the vertical engaging faces is parallel to one of a plurality of bisectors passing through the central axis and extending along a thickness direction of the screw head.