It is a type of threaded insert. There are 2 varieties: a person is created to kind a bulge about the back facet of the panel to be a screw is tightened in its threads. The opposite is likewise drawn in utilizing a screw, but is drawn to the sleeve https://reinforced-plastic-materi01986.bloguetechno.com/the-best-side-of-threaded-inserts-for-plastics-62238087