from the octagonal member.
U.S. Pat. No. 4,361,412 to Stolarczyk describes a body that is provided defining a center axis and having at least four adjacent sides equally spaced from and about the center axis and disposed normal to adjacent 60.degree. relatively angularly displaced radii of the center axis. Each of the sides includes opposite ends and at least the center two sides of the four adjacent sides are interrupted centrally intermediate their opposite ends by a pair of spaced torque transfer surfaces spaced apart generally one-third the length of the corresponding side and equally from the opposite ends thereof. The surfaces are disposed on radii of the center axis. In a first form of the invention only four of the adjacent sides are provided and the end twoengage an associated hexagonal fastener with substantially surface to surface contact on each fastener side in close proximity to, but always spaced from, a fastener corner, thereby providing a maximum practical moment arm between wrench and fastener, and yet avoiding deteriorating engagement between the wrench and the fastener corners. The clockwise and counterclockwise drive portions of the wrench occupy the middle about 1/2of each uniform 60.degree. segment of the wrench opening. The space on the internal surface configuration of the wrench between adjacent pairs of drive portions is relieved just enough to avoid interference with the corners of the fastener, thereby providing a rotational clearance of about 25.degree. with the fastener, the precise angular amount depending on manufacturing tolerances in the wrench and fastener. This extended rotational clearance