DRIVE CONFIGURATION WITH DIFFERENTIAL DRIVING SURFACES

摘要

A wrenching member (10) includes at least two spaced-apart and substantially oppositely facing drive surfaces (20, 21), each of which has a roughened region (26, 27) and an unroughened region (28, 29) thereon, with the roughened region (26, 27) being disposed adjacent to one end of the one of the drive surfaces (20, 21) and adjacent to the other end of the other drive surface (20, 21) so as to afford a differential wrenching force in one direction than in the opposite direction.