How to use a rivet nut tool
Updated: 16 October 2026
The lever tool is on the bench, the mandrels are in the case, and the panel is still clean. How to use a rivet nut tool is one order: protect your eyes, clamp the work, match the mandrel, screw the nut on until it sits level, squeeze once, then unscrew the mandrel. Do that on scrap of the same thickness before you touch the real panel. The [rivet nut pliers comparison](/hub/pliers/rivet-nut-pliers) is the buying set, not the stroke. Products Compared followed UK manuals, not a lab session with these kits. A qualifying purchase can earn a commission at no extra cost to you.
The lever tool is on the bench, the mandrels are in the case, and the panel is still clean.
The lever tool is on the bench, the mandrels are in the case, and the panel is still clean. How to use a rivet nut tool is one order: protect your eyes, clamp the work, match the mandrel, screw the nut on until it sits level, squeeze once, then unscrew the mandrel. Do that on scrap of the same thickness before you touch the real panel. The rivet nut pliers comparison is the buying set, not the stroke. Products Compared followed UK manuals, not a lab session with these kits. A qualifying purchase can earn a commission at no extra cost to you.
Our top picks
| Badge | Product | Mechanism | Largest thread | Handle length | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  LIBRATON LIBRATON ratchet rivet nut tool, M5–M12 | Ratchet | M12 | Ratchet | 7.6 | about £65.99 | View offer |
 Proster Proster 14 inch rivet nut tool, M3–M10 | Long lever | M10 | 14 inch | 8.5 | about £35.99 | View offer | |
| Preis-Tipp |  eSynic eSynic 8 inch rivet nut tool, M3–M6 | Short lever | M6 | 8 inch | 8.3 | about £24.02 | View offer |
Before the first squeeze
Wear safety glasses before the handles move. The Rivet Company's N200 manual says so, Sealey's sheet asks for approved eye or face protection, and the Health and Safety Executive lists projectiles as a reason for eye protection. Clamp the sheet. Sealey tells you not to hold the workpiece. At work, the Provision and Use of Work Equipment Regulations 1998 still require suitable equipment.
The hole should already match the nut in your hand. This page does not reprint a drill chart, because M6 is not one diameter. If you have not drilled yet, use rivet nut hole size. A bolt-clearance hole is usually too large, and the pliers cannot shrink it.
Set the nut
Match the mandrel to the thread first. An M6 mandrel in an M5 nut strips one of them. Kennedy's inserter quotes a 7 mm effective stroke on that tool, and Sealey's long-arm note talks about 6 mm and below on that model. On a kit with no scale, learn the stroke from scrap. Screw the insert on until the mandrel end is about level with the face of the nut, or until the insert is fully home, which is how the N200 puts it. A long tail of thread lets the nut cock. Bury the mandrel so deep that the nose hits the flange and you crush the head before the body collapses. Then insert the nut, close the handles fully, and release.
On the Kennedy tool the release is the thumb wheel turned anticlockwise. On the N200 you turn the adjuster after the arms have closed. Forcing the handles open while the mandrel is still threaded into a half-set nut is how threads strip. If your kit has no thumb wheel, follow the sheet in the case. The nut stays in the panel. The mandrel comes out on its own thread. UK notes on the eSynic 8 inch tool say M6 needs a very strong grip. More force after the thread has started to tear is the wrong fix.
Stroke too short or too long
The N200 manual draws the two failures. Stroke too short leaves the nut loose: the handles may have closed, and the insert still turns. Lengthen the stroke on scrap and use a new nut. Stroke too long over-crushes the body, the thread distorts, and the mandrel can lock so it will not unscrew. Shorten the stroke. If the mandrel is already stuck, stop.
PEM Europe's grip note is a cause, not a chart. Sheet thinner than the nut's minimum grip over-sets and can distort the thread. Sheet thicker than the maximum under-sets, so the bulge never locks. You fix that by choosing another nut, not by leaning harder. Spinning after a tidy-looking set is often an oversized hole, a smooth thin sheet, or the wrong grip. Rivetwise names those for UK buyers. A hex body in a hex hole resists turning when a plain round nut will not.
When to stop
Stop when the mandrel is bent, the thread on it is torn, or the handles no longer meet. A bent mandrel sets the next nut crooked and can snap. A spare in the size you use is cheaper than a second panel. Stop when the joint is structural, or when the stack is thicker than every grip you can buy. A hand tool that has stalled on steel is telling you the insert or the mechanism is wrong.
Stop, and get someone who knows the vehicle, when the panel sits next to fuel, an airbag or a loom you cannot identify. These kits are not covered by BS EN ISO 11148-1, which is for powered setters. If the handles cannot open, change tool rather than shortening your grip. That choice is on rivet nut pliers vs ratchet.
Common questions
Which way do I turn the knob to release the tool?
On the Kennedy manual the thumb wheel releases anticlockwise after the handles have closed. The N200 uses its adjuster in the same spirit: set, squeeze, then release so the mandrel can unscrew. If your kit's own sheet shows the opposite, follow that sheet. Forcing the handles apart while the nut is still threaded on is how the mandrel strips.
How far should the nut screw onto the mandrel?
Until the mandrel end is about level with the face of the nut, or until the insert is fully home, as the N200 describes. Too little thread and the nut cocks. Too much and the nose crushes the head. One scrap nut shows you the picture faster than a ruler will.
What if the handles close and the nut is still loose?
The stroke is too short, the sheet is thicker than the grip, or the handles did not close fully. Lengthen the stroke slightly and try a new nut in scrap. Do not keep heaving on the loose one. If an 8 inch tool is already at the limit of your grip on M6, more force is the wrong fix.
What if the mandrel will not unscrew?
The stroke was probably too long, so the thread has distorted around the mandrel. If it frees on the release wheel, shorten the stroke and use a new nut. If it does not free, that insert is scrap. Drill it out only if you can do so without opening the hole past the next nut's chart.
Do I set the stroke on the real panel?
No. Use an offcut of the same thickness, with the same paint or gasket if that layer is part of the stack. Move to the panel only after a scrap nut sits flat and a screw starts by hand. The finished face is a poor place to discover that the stroke was long.
Related pages
Sources
Public UK sources and the amazon.co.uk listings in this comparison, checked on 15 October 2026. Shelf prices and star lines are the figures in the display file.
- Normandy Fasteners: rivet nut hand tools (retrieved 15 October 2026)
- Kennedy M3–M12 inserter manual (Cromwell PDF) (retrieved 15 October 2026)
- Sealey AK3984 / AK3985 instructions (retrieved 15 October 2026)
- PUWER 1998, regulation 4 (retrieved 15 October 2026)
- HSE: using the right type of PPE (retrieved 15 October 2026)
- JC Fasteners: blind rivet nut technical guide (retrieved 15 October 2026)
- Fixings Megastore: rivet tooling (retrieved 15 October 2026)
- amazon.co.uk listings for the eight ASINs in this comparison (retrieved 15 October 2026)