Fastening socket for assembling structures and associated attachment

Fastening socket for assembling at least two previously drilled structures, said socket extending along a main axis between a first and a second open ends, said socket comprising a substantially cylindrical body and an enlarged head;

• said enlarged head comprising first mounting surfaces capable of being assembled to a first installation element and for rotationally locking said first installation element about the main axis,
• characterised in that it comprises a first recess substantially cylindrical extending along the main axis from the first end, said first recess leading to a planar shoulder substantially perpendicular to said main axis, the first recess and the planar shoulder being received inside the enlarged head, the first mounting surfaces are formed by an inner surface of the first recess;
• and
• wherein first mounting surfaces extend from the first end of the socket but do not reach the planar shoulder, the first mounting surfaces thereby defining a recessed volume with said planar shoulder.