Generic shop name for a rivet nut, a tubular insert with an internal thread that is set by a tool pulling on a threaded mandrel, which collapses the body into a bulge behind the sheet. It gives a load-bearing thread in sheet metal, tubing and panels where there is no access to the back and the wall is too thin to tap. Hole size and grip range must match the insert, or it spins in the hole the first time a screw is tightened.
Rivnuts in the frame rail are spinning, so drill them out and go up to the hex-body ones.
Hex-body or knurled rivnuts are the ones to use anywhere a screw will come out more than once.
Also heard as
- rivet nut
- nutsert
- blind nut
Related terms
Pop rivet
Shop name for a blind rivet: a hollow rivet set from one side by pulling a mandrel that snaps off when tight.
Spinner
A fastener that just turns without tightening or loosening, because its thread, insert or captive nut gave up.
Helical insert
A coil of diamond-section wire screwed into an oversize tapped hole to repair a stripped thread or armor a soft one.
Huck bolt
Shop name for a lockbolt: a grooved pin with a collar swaged on by a tool, giving a joint that will not vibrate loose.