Patent ID: 7159492

Claim:
A wrench tool comprising an orifice having a predetermined geometry for controlling the rotation of a hexagonal work piece, said orifice being substantially cylindrical and comprising an array of only eighteen longitudinal grooves positioned therein substantially forming a symmetrical pattern around an imaginary central axis, said eighteen grooves being formed and spaced apart so as to create an array of only eighteen longitudinal protuberances, said protuberances substantially forming a symmetrical pattern around said imaginary central axis for engagement with said work piece, each said protuberance further being formed having at least two outer engaging surfaces substantially forming an outer engaging angle within the range of 223 through 237 degrees inclusive and, said protuberances being positioned apart relative to each other and to said imaginary central axis by predetermined dimensions whereas the least distance between said imaginary central axis and each said protuberance being a predetermined Dimension A, and the least distance between any eight adjacent protuberances being a predetermined Dimension B, and, Dimension A being substantially equal to or greater than 52% of Dimension B and substantially equal to or less than 55% of Dimension B.