A rivet nut has a collapsible shell with internal threads that allow an installer to place structural threads in thin materials without reaching behind the material to thread a nut on the end of a fastener. Specialized tools are required to install a rivet nut in a material and provide a strong connection in the thin material. Some of the tools are designed to provide the hole for installation, and others are designed to collapse the outer shell of the nut to keep it in place in the material. Using the tools incorrectly will allow the installed rivet nut to spin in the mounting hole or pull from the thin material. Both situations result in a weak connection that will require the installer to install another rivet nut.
Drill bits are the first tool needed to install a rivet nut in the base material. The size of the rivet nut designates the size of the drill bit required to drill a hole in the material. Since rivet nuts work on tight tolerances, an exact size hole is required to ensure the rivet nut does not sit loose after installation. Each rivet nut is supplied with the hole diameter needed to ensure a tight installation, and the drill bit size cannot be substituted. A drill motor holds and rotates the drill bit during the drilling process.
Variable speed drill motors allow an installer to change the rotation speed of the drill bit, which is a valuable asset when drilling harder materials that work-harden when drilled. Work hardening will cause the end of the drill bit to dull, glow and eventually melt before it has a chance to drill through the base material. As the work-hardened area cools, the installer will have a difficult time inserting a rivet nut in the drilled hole. After the correct size hole is drilled in the material, another specialized tool is needed to secure the nut in the base material.
Rivet nut tools consist of a threaded mandrel attached to two handles. Above the handles sits a head that has an adjustment that allows the installer to adjust the amount of pull exerted by the tool. The correct material thickness is required to ensure the collapsed part of the nut remains tight in the material. Improper use of a rivet nut tool will cause the threaded mandrel to snap and ruin the threads sitting inside the collapsed part of the nut body.