It's really a kind of threaded insert. There are two kinds: a single is designed to type a bulge to the again side on the panel to be a screw is tightened in its threads. The other is in the same way drawn in employing a screw, but is drawn https://manuelmgyod.onesmablog.com/new-step-by-step-map-for-threaded-inserts-for-plastics-66726656