The rivet nut is a one-piece internally threaded and counterbored tubular aluminum rivet that can be pulled up or headed while working entirely from the side, forming a bulge or head on the blind side. This upset is large enough to resist being pulled through metal or plastic even under conditions of eccentric load. It overcomes the difficulty of installing brackets, handles or other attachments to tubular pieces. Rivnut is threaded onto pull-up stud of a hand or power-heading tool. Rivnut on header tool mandrel, inserted in drilled hole ready for installation. Arrow indicates direction of mandrel movement as tool is operated. Mandrel retracts pulling threaded portion of Rivnut shank toward blind side of work, forming bulge around unthreaded shank area. Rivnut is clinched securely in place. Unthreading the tool mandrel leaves internal Rivnut threads