How to Use a Rivet Nut Tool | Threaded Inserts Done Right

Learning how to use a rivet nut tool is simpler than it looks. The tool pulls a threaded insert tight against the back of a panel, leaving clean machine threads on the front. You get a strong, reusable anchor in thin metal, plastic, or fiberglass — no welding needed.

The Core Process: Five Steps That Apply To Every Tool

Every rivet nut tool works on the same principle: pull the insert’s body flat behind the panel so it grips tight, then unscrew the tool. The exact hand motions differ, but the sequence stays the same.

• Open the tool fully and fit the correct mandrel and nosepiece for your rivet nut size.
• Thread the rivet nut onto the mandrel until it bottoms out — fully engaged, not just started.
• Place the insert into a hole drilled specifically for that insert’s body size.
• Squeeze the handles or pull the trigger to collapse the body behind the workpiece.
• Release or reverse the tool to unscrew it from the installed insert.

That’s the entire loop. The nuance lives in the details: matching the mandrel, sizing the hole, and reading the tool’s action so you don’t force anything.

Matching The Mandrel And The Hole (Get This Wrong And Nothing Works)

The mandrel threads into the rivet nut, so it must match the insert’s internal thread size perfectly. The hole must match the insert’s body diameter, not the threads.

The Rivet Company’s manual puts it plainly: drill a hole “fractionally larger” than the rivet nut body, fit the correct mandrel, thread the rivet nut on, insert it into the hole, and squeeze until the tool reaches its stop. A hole that’s too small blocks the insert from seating; one that’s too large lets the insert spin or pull through when you set it.

On the tool itself, the working stroke often needs adjustment. Suncor’s instructions for its S0380-0000 model spell out the sequence: open the handles, thread the insert on, adjust the stroke by rotating the outer sheath, tighten the locking nut, then set the insert. That stroke adjustment is what controls how much the insert collapses — get it set once for your material thickness, and every install after that is consistent.

Setting The Insert: Squeeze, Stop, And Release

With the insert threaded on and placed in the hole, close the handles until they stop. Rivet Nut USA’s 140-2000 manual says to close until the handles stop, then repeat if needed until the insert is fully collapsed. A correctly set rivet nut sits flush and tight to the panel and does not rotate when you torque a bolt into it.

When the insert is set, the tool needs to come off. On most manual tools, you turn the rear assembly counterclockwise to unscrew the mandrel from the installed insert. Suncor describes rotating the installation knob counterclockwise to release; Rivet Nut USA says turn the rear assembly the same direction. If the tool feels stuck, do not force it — Suncor specifically warns against forcing removal and directs you to the Allen wrench method instead.

Forcing the tool is the fastest way to strip the insert’s internal threads or damage the mandrel. Fully closing the levers reduces stress on the tool and improves the install quality, but that’s about firm, complete action — not about muscling past resistance.

Common Mistakes And How To Avoid Them

Knowing what goes wrong saves you a box of ruined inserts. These five mistakes account for most failed installs:

• Wrong mandrel or nosepiece. A mismatched setup can damage the mandrel thread. Check the fit before you start.
• Wrong hole size. Too small blocks insertion; too large lets the insert fall out or fail to engage the panel.
• Incomplete threading. The insert must be fully on the mandrel, or it will cross-thread when set.
• Over-forcing. Excess force strips insert threads or the mandrel. The tool has a stop for a reason.
• Skipping the final check. Confirm the insert is fully collapsed and doesn’t spin in the hole before you move on.

Wear eye protection when using a nut riveter — The Rivet Company’s manual calls this out explicitly. Loose debris and broken inserts can eject unexpectedly.

These steps cover manual and cordless tools, but exact controls vary by model. Always follow the specific manufacturer manual for your tool. If you’re shopping for your first tool, our tested roundup of the best tools for rivet nuts breaks down which handles what, so you can match the tool to the jobs you actually do.