Attachment member with an end cavity in a threaded terminal portion, male element, operation tool and gauge including such a male element

摘要

The unit has a threaded end portion, and an end face with a recess (10) and multilobed footprint. The recess is provided with a peripheral edge (12) in the form of multilobed continuous curved line. A lobe (L) is defined in a section by a continuous series of three arcs. One of the arcs is convex circle (14) having a first radius around which a concave circular arc (16) having a second radius is arranged on either side. The lobe is connected to an adjacent lobe by a third convex circular arc (18) having a third radius greater than the first radius. Independent claims are also included for the following: (1) a male element comprising a cylindrical center section (2) an assembly tool comprising an end (3) an inspection gauge comprising a grippable body.