Abstract: A socket having a socket body which is accurate in position when in use. The body is provided with an internal blind bore having an open end and a closed end. The blind bore defines or has a portion defined by inner surfaces which converge in a direction toward the open end of the blind bore and diverge toward the closed end. This bore portion is spaced axially from the open end. Within this portion of the bore is disposed a locking element made of at least two segments that have an axial extent less than the length of the above-mentioned portion. The segments have outer side surfaces which are complementary with the converging inner surfaces of the portion of the blind bore. They are each provided with a thread and jointly define a bore of lesser diameter than the open end and accordingly of lesser diameter than an anchor bolt insertable axially into the socket body.