What a rivet nut tool does and when you need one
A rivet nut installation tool — also called a rivet nut setter or threaded insert tool — fastens a hollow rivet nut (a threaded metal insert) into a hole in sheet metal, plastic, or composite material. Once installed, the rivet nut creates a permanent threaded hole where you can bolt components together repeatedly without stripping the base material.
You need this tool when you're working with thin sheet metal or materials that can't hold a traditional bolt directly. Aircraft maintenance, automotive body panels, appliance assembly, and industrial equipment all rely on rivet nuts because they distribute load across a wider area than a bolt alone and won't pull through or strip out over time.
The tool works by pulling the rivet nut's internal mandrel (a stem inside the insert) as you squeeze the handle. This mandrel draws the rivet nut's collar inward, expanding the back side of the insert against the material and locking it permanently in place. Once set, you remove the tool and the mandrel breaks off inside the nut, leaving a clean threaded hole.
Key Takeaways
- Rivet nut tools come in manual, pneumatic, and hydraulic versions, with manual tools suitable for light work and pneumatic tools for production environments.
- You must use the correct mandrel size for your rivet nut diameter, or the tool will not seat the nut properly and may damage the material.
- The hole in your base material must be the exact size specified by the rivet nut manufacturer — too large and the nut spins, too small and it won't fit.
- Manual rivet nut tools require significant hand strength and can cause hand fatigue on large jobs, making pneumatic tools a practical choice for high-volume work.
Manual versus pneumatic rivet nut tools
Manual rivet nut tools are hand-operated and require you to squeeze a trigger or pull a handle repeatedly to set each nut. They cost between $30 and $150 depending on the mandrel sizes they accept and the build quality. Manual tools work well for occasional repairs, prototype work, or jobs where you're installing fewer than 20 or 30 rivet nuts. They need no power source and are portable, making them practical for field work or tight spaces.
Pneumatic (air-powered) rivet nut tools use compressed air to drive the mandrel and require an air compressor and hose. They cost $200 to $600 and are much faster — each nut takes one or two seconds instead of five to ten seconds with a manual tool. Pneumatic tools reduce hand fatigue and are standard in manufacturing, assembly plants, and shops where speed matters. They do require a compressor rated for the tool's air consumption, typically 4 to 6 cubic feet per minute at 90 PSI.
Hydraulic rivet nut tools exist but are less common in small shops. They're used for very large rivet nuts or when working with extremely hard materials, and they cost significantly more than pneumatic options.
Choosing the right mandrel size for your rivet nut
Every rivet nut tool comes with interchangeable mandrels — the part that actually pulls the rivet nut. Mandrels are sized to match specific rivet nut diameters, typically ranging from 1/8 inch to 1/2 inch or larger. Using the wrong mandrel size is the most common installation mistake and will result in a loose, spinning rivet nut or a damaged insert.
Before you buy or use a tool, identify the diameter of the rivet nut you're installing. This is printed on the nut itself or on the packaging. Then verify that your tool comes with or can accept the matching mandrel. Some tools accept a wide range of mandrels and come with a set of four to six sizes. Others are fixed to a single size, which makes them useful only for one specific job.
If you're buying a tool for ongoing work, look for one with a quick-change mandrel system so you can swap sizes without tools. This saves time and reduces the chance of using the wrong mandrel by accident.
Drilling the correct hole size
The hole you drill in your base material must match the rivet nut's specifications exactly. Rivet nut manufacturers publish a hole size chart for each nut diameter — for example, a 1/4-inch rivet nut typically requires a 0.265-inch hole, not a 1/4-inch hole. Using the wrong hole size is the second most common cause of installation failure.
If the hole is too large, the rivet nut will spin inside it and won't seat properly. If the hole is too small, the nut won't fit at all and you'll damage the tool trying to force it. Drill the hole with a bit that matches the manufacturer's specification, and use a center punch to mark the spot before drilling so the bit doesn't wander on sheet metal.
For production work, use a drill press or a CNC machine to hold tolerances. For one-off repairs, a hand drill works if you're careful to keep the bit perpendicular to the material.
Step-by-step installation process
Start by inserting the rivet nut into the hole from one side of the material. The nut should sit flush against the surface with the threaded end facing outward. If it doesn't sit flat, the hole is the wrong size or the nut is damaged.
Slide the mandrel into the center of the rivet nut. The mandrel should fit snugly and not rattle. Position the tool's nose cone over the mandrel so it's centered and square to the material. On a manual tool, this means holding the tool perpendicular to the surface. On a pneumatic tool, the nose cone will guide itself if you press it firmly.
Squeeze the trigger or pull the handle smoothly and steadily. You'll feel resistance increase as the mandrel pulls the nut's collar inward. Continue until you hear or feel a sharp click or pop — this is the mandrel breaking off inside the nut, which means the nut is fully set. Stop when ready; over-pulling can damage the nut or the tool.
Remove the tool and inspect the nut. The collar should be expanded tightly against the back of the material, and the nut should not spin when you try to turn it by hand. If it spins, the installation failed and you'll need to drill out the nut and start over with a new one.
Common installation problems and how to avoid them
A spinning rivet nut usually means the hole was too large or the mandrel didn't pull hard enough. This happens most often with manual tools on thick material or when the operator didn't pull all the way through. Drill out the failed nut with a bit slightly larger than the hole, remove it, and try again with a new nut and the correct hole size.
A mandrel that won't break off or gets stuck inside the tool usually indicates you're using the wrong mandrel size or the rivet nut is damaged. Stop when ready and remove the tool. Forcing it will break the tool. Check that the mandrel matches the nut diameter and that the nut itself isn't bent or deformed.
Cracked or split material around the nut happens when the hole is too small or when you over-pull the tool. The expanding collar pushes too hard on the material and splits it. Use the correct hole size and stop pulling as soon as you feel the mandrel break. On thin or brittle materials like aluminum or plastic, use a backing plate — a flat steel washer or plate on the opposite side of the material — to distribute the load and prevent splitting.
Maintenance and storage
Manual rivet nut tools need minimal maintenance. Wipe the mandrel and nose cone clean after each use to remove metal shavings and debris. Store the tool in a dry place and keep the mandrels organized so you grab the right size every time. Check the handle or trigger for cracks before each use; a broken handle can pinch your hand.
Pneumatic tools should be drained of moisture from the air line after each day of use. Water in the air line corrodes the internal piston and seals. Attach a moisture trap to your air compressor outlet if you don't have one already. Lubricate the tool according to the manufacturer's instructions — most require a few drops of pneumatic tool oil in the air inlet every few hours of use.
Store mandrels in a labeled case or drawer so you know which size is which. A bent or damaged mandrel will produce poor results, so handle them carefully and replace them if they become deformed.
Frequently Asked Questions
Can I use a rivet nut tool on plastic or composite materials?
Yes, but with caution. Plastic and composites are softer than metal and can crack or split more easily. Use a backing plate on the opposite side to distribute the load, pull the tool more slowly, and stop as soon as the mandrel breaks. Test on scrap material first to see how the material responds.
What's the difference between a rivet nut and a regular threaded insert?
A rivet nut is set by pulling a mandrel and is permanent once installed. A threaded insert is usually screwed into a hole and can be removed if needed. Rivet nuts are faster to install and don't require a pre-threaded hole, making them better for production work. Threaded inserts are better when you might need to remove or replace the insert later.
Do I need a special tool to remove a rivet nut?
No special tool exists for removal. You drill out the nut with a bit slightly larger than the hole, which destroys the nut. Once removed, you can install a new nut in the same hole if the hole is still the correct size. If drilling enlarged the hole, you'll need to drill a larger hole and use a larger rivet nut.
How much hand strength do I need to use a manual rivet nut tool?
Manual tools require significant grip strength, especially on larger nut sizes or thick materials. Most people can set 10 to 20 nuts before hand fatigue becomes a problem. If you're installing more than 30 nuts, a pneumatic tool will save your hands and complete the job faster.
Can I use a rivet nut tool on stainless steel or aluminum?
Yes to both. Stainless steel is harder and requires more pulling force, so a pneumatic tool is practical for high-volume work. Aluminum is softer and splits more easily, so use a backing plate and pull smoothly without jerking. Always use the correct hole size for the material and nut diameter.