Patent ID: 7331744

Claim:
In a fastener having an axial drive socket for receiving a wrench key driver, the fastener including a shaft with a first end and a second end, an enlarged head at one of the first and second ends, and male threads at the other of the first and second ends, and the axial drive socket being located in one of the first and second ends of the shaft, the improvement comprising: a first plurality of sides of the axial drive socket, said first plurality of sides of the axial drive socket being substantially equidistant from a center of the fastener and from each other, each of the sides of the first plurality of sides including a curved radius portion and one flat surface portion located adjacent to and substantially tangential to the curved radius portion; a second plurality of sides of the axial drive socket forming rounded lobes of substantially equal radius not including a flat surface portion, said second plurality of sides of the axial drive socket being substantially equidistant from the center of the fastener and from each other, and said first and second plurality of sides of the axial drive socket being alternatingly arranged about the axial drive socket; and curved recesses located between the first plurality of sides and the second plurality of sides, each of said flat surface portions of said first plurality of sides being connected to a corresponding adjacent lobe of said second plurality of sides by one of said curved recesses, and each of said curved radius portions of said first plurality of sides being directly connected to a corresponding adjacent lobe of said second plurality of sides by one of said curved recesses.