A rivet nut also known as a blind nut or nut-sert, is a one-piece internally threaded and counter bored tubular rivet that can be anchored entirely from one side There are two types one is designed to form a bulge on the back side of the panel as a screw is tightened in its thread They provide thread into thin sheet material rivet nuts provide an internal thread, bolts an external thread At the same time they can also function as a blind fastener to join two materials together.