FIELD: construction.
SUBSTANCE: invention relates to a fastening facility comprising a threaded end part, the end side of which comprises a cavity, made as capable of insertion of a attachment in it with responding shape, at the same time the specified cavity comprises a peripheral edge in the form of a curved continuous multi-tab line. Each tab is formed in the section with a continuous sequence of circular arcs, namely, with a convex first circular arc having the first radius, at one and other side of which there is a concave second circular arc with the second radius. Each tab is coupled with the adjacent tab via the convex third circular arc with the third radius that exceeds the first radius. The invention also relates to the covered element that has a relief shape corresponding to the cavity shape, and also a check template comprising such covered element.
EFFECT: creation of a threaded fastening facility, which may be installed with a torque exceeding a torque of available fastening facilities.
