Making a rivet nut tool allows you to install a rivet nut in a thin piece of metal without spending a lot of money on an expensive rivet nut setting tool. A rivet nut has a plated body that has a weak spot designed near the top of the nut, directly below a flange that holds it tight to a piece of metal. When the rivet nut is compressed, the weak spot of the body expands and pulls the rivet nut flange tight to the metal. The key to making a rivet nut tool is to create a tool that holds the flange of the nut tight to the top of the metal while pulling the body of the nut toward the underside of the metal.
Thread a hex nut on the threads of a 50 mm (2 inch) bolt. Spin the nut until the bottom of the nuts sits 18 mm (3/4 inch) above the bottom of the bolt threads.
Turn the bolt upside down. Slide a flat washer on the end of threaded end of the bolt. Allow the washer to sit against the bottom of the hex nut.
Align the flanged end of a rivet nut with the end of the bolt. Turn the rivet nut clockwise until the rivet nut tightens against the bottom of the bolt. Turn the hex nut counterclockwise until the washer tightens to the rivet nut flange to assemble your rivet nut tool.
Push the rivet nut into a drilled sheet metal hole. Hold the hex nut with one wrench and turn the head of the bolt three turns clockwise to lock the rivet nut in the sheet metal. Turn the bolt head counterclockwise to remove your rivet nut tool from the installed rivet nut.