Abstract: A wrench for turning a fastener nut having a central axis and an even-numbered plurality of flat bounding surfaces parallel to the fastener access wherein diametrically opposite pairs of surfaces are parallel to each other and the bounding surfaces intersect in adjacent pairs to form fastener corners. The wrench includes a fastener nut socket defined by a central socket axis. The socket includes a plurality of uniformly spaced peripherally and radially disposed sides and a plurality of uniformly spaced fastener corner clearance recesses disposed between sides. Each side includes a planar surface and a pair of complimentary surfaces, wherein a complimentary surface diverges outwardly from each end of the planar surface at an angle of approximately three degrees (3.degree.). The planar surface has a length approximately equal to 0.35 times (.times.) the minor diameter of the fastener nut to be driven.

Abstract: A wrench for turning a fastener nut having a central axis and an even-numbered plurality of flat bounding surfaces parallel to the central axis with diametrically opposite pairs being parallel to each other. The wrench includes a fastener nut engaging socket defined about a central socket axis by a plurality of uniformly spaced peripherally and radially disposed protuberances and plurality of uniformly spaced corner recesses disposed between the protuberances. Each protuberance includes outwardly diverging angularly related straight engaging surfaces for registry with the flat surfaces on the fastener nut. Each recess is comprised of a first arcuate surface tangential to a circle about the central axis of the socket and transitional surfaces converging from the adjacent protuberances toward the first arcuate surface.

Abstract: A wrench for turning a fastener nut having a central axis and an even-numbered plurality of flat bounding surfaces parallel to the central axis with diametrically opposite pairs being parallel to each other. The wrench includes a fastener nut engaging socket defined about a central socket axis by a plurality of uniformly spaced peripherally and radially disposed protuberances and plurality of uniformly spaced corner recesses disposed between the protuberances. Each protuberance includes side-by-side angularly related straight engaging surfaces at substantially 142.degree. outside obtuse angles to each other for registry with the flat surfaces on the fastener nut and complementary side surfaces outwardly diverging from said engagement surfaces. Each recess is comprised of a first arcuate surface tangential to a circle about the central axis of the socket and transitional surfaces converging from the side surfaces of adjacent protuberances toward the first arcuate surface.