Abstract: A tubular insert designed to be positioned in a through-orifice of a sandwich panel. This tubular insert comprises a tubular body and at least one tab that has a first end connected to the tubular body and a second end at a distance from the first end, the tab being able to move between a deployed position in which the second end is moved away from the tubular body and a retracted position in which the second end is positioned at the tubular body, the latter having, for each tab, a cutout delimiting the tab and an opening when the tab is in the deployed position. Also a sandwich panel having at least one such insert and a method for placing such an insert.

Abstract: An assembly comprising a nut, in addition to a retaining system which is configured to retain the hole of the nut substantially in the extension of a through-hole of a part. The retaining system comprises at least two resilient tabs which are configured to be housed in the through-hole of the part, the free ends of the resilient tabs being positioned, in the undeformed state, on a circle having a greater diameter than an internal diameter of the through-hole. Also a mounting system comprising such a retaining system for a nut.

Abstract: A sleeve fastening system fastened to a joist pierced with a hole and receiving two pipes and including a cylinder fitted into the hole of which each end receives a pipe, wherein the wall of the cylinder has cut into it at least one tunnel, a flange, each tunnel having openings that emerge on either side of the flange that has a bearing face bearing against the joist and a free face, and for each tunnel, a holding system having a link, a shoe and a locking system, the link being housed in the tunnel with the shoe blocked in a first opening on the side of the free face and wherein the link exits via a second opening on the side of the bearing face and wherein the locking system attaches.