You cannot tap threads directly into thin sheet metal because there is not enough thickness to hold the bolt. A Rivnut solves this problem. It is inserted into a pre-drilled hole and squeezed using a special tool. The squeeze collapses the sleeve behind the panel, locking the Rivnut in place. You are left with a strong, threaded brass or steel insert ready for a bolt. They are useful for mounting skid plates, firewalls accessories, or replacement door panels. Keep the tool straight during installation to avoid setting the insert crooked.
Mechanic Glossary
Rivnut
A tubular metal rivet with internal threads that is compressed in place to provide a permanent, threaded socket in thin sheet metal.
Frequently Asked Questions
The Rivnut packaging will list the exact hole size. If the hole is too large, the Rivnut will spin when you try to tighten the bolt.
Use a Rivnut tool to compress it further. If that fails, you must drill it out and install a new one.
You can use a bolt, a nut, and two washers to squeeze it, but the dedicated tool is much faster and ensures even compression.
Standard Rivnuts are not sealed. Use closed-end Rivnuts or apply a dab of silicone sealant around the flange if waterproofing is needed.