This is a type of threaded insert. There are 2 varieties: a person is designed to type a bulge within the back side from the panel as being a screw is tightened in its threads. The other is similarly drawn in employing a screw, but is drawn into your sleeve https://clamp-onthreadedadapter21964.thezenweb.com/inserts-for-metal-alloy-an-overview-64198570