How Do Pop Rivets Work – For Permanent Metal-To-Metal Fastening

ByJim Boslice Metalworking & Fabrication

Pop rivets, or blind rivets, work by pulling a central mandrel through a hollow rivet body using a hand-operated tool. This action expands the rivet body on the blind side, clamping your materials together permanently.

You’re working in the garage, staring at two pieces of sheet metal that need to be joined, but there’s no way to reach the backside to hold a nut. It’s a common frustration for DIYers, but that is exactly where understanding how do pop rivets work changes the game for your fabrication projects.

I’ve spent years in the workshop, and I still remember the first time I used a rivet gun. It felt like magic—one satisfying squeeze and the metal was locked tight, no welding required. If you want to master this essential skill, you’re in the right place.

In this guide, I’ll break down the mechanics behind these fasteners, show you how to select the right materials, and walk you through the process so you can tackle your next project with total confidence. Let’s get into the mechanics of the workshop.

Understanding the mechanics of how do pop rivets work

At its core, a pop rivet is a two-piece assembly consisting of a tubular rivet body and a central pin called a mandrel. Unlike a bolt that requires a nut on the other side, a rivet is designed for “blind” applications where access is limited to only one side of the workpiece.

When you place the rivet into a pre-drilled hole and actuate your rivet gun, the tool grips the protruding mandrel. As the gun pulls the mandrel back, the head of the mandrel compresses the tail end of the rivet body against the back of your material.

This action causes the rivet body to bulge outward, creating a secondary head on the backside. Once the rivet is fully set and the two pieces are tightly clamped together, the mandrel snaps off at a predetermined notch, leaving you with a clean, permanent mechanical joint.

Essential tools for your rivet setup

You don’t need an expensive shop setup to get started with riveting. A high-quality hand rivet gun is the standard tool for most home workshops and garage tinkerers, offering excellent control for small to medium-sized projects.

  • Hand Riveter: The classic tool for occasional repairs and hobby work.
  • Drill and Bits: You must drill a hole slightly larger than the rivet diameter for a smooth fit.
  • Deburring Tool: Always clean up the hole edges to ensure the rivet sits flush against the surface.
  • Safety Glasses: Essential for protecting your eyes from metal shavings during drilling.

If you find yourself doing high-volume work, such as building a utility trailer or modifying a race car, you might consider upgrading to a pneumatic or cordless electric rivet gun. These tools save your grip strength during long assembly sessions, but for 90% of DIY tasks, the manual tool is perfectly sufficient.

Selecting the right materials for your project

Not all rivets are created equal, and choosing the wrong material can lead to galvanic corrosion or structural failure. Always match your rivet material to the base material you are fastening to ensure long-term durability.

Aluminum rivets are the most common choice for general DIY projects. They are easy to set, resistant to corrosion, and work perfectly with aluminum sheeting or thin-gauge steel. If you are working with stainless steel, ensure you use stainless rivets to maintain strength and weather resistance.

Think about the grip range of the rivet as well. This is the total thickness of the materials you are joining. If your rivet is too short, it won’t form a proper head on the back; if it’s too long, it may bend or crush instead of clamping securely.

Step-by-step guide to installing a pop rivet

Proper installation is the secret to a professional-looking finish. Follow these steps to ensure your joints are as strong as possible, and you will quickly see why understanding how do pop rivets work is a foundational skill for any metalworker.

  1. Measure and Mark: Accuracy is key. Use a center punch to mark your hole location so the drill bit doesn’t wander.
  2. Drill the Hole: Use a drill bit that is just a fraction larger than the rivet shank. If the hole is too big, the rivet will be loose; if it’s too small, you’ll struggle to insert it.
  3. Deburr: Use a file or a specialized deburring tool to remove sharp metal burrs from both sides of the hole.
  4. Insert and Set: Place the rivet body into the hole, insert the mandrel into your rivet gun, and squeeze the handles until the mandrel snaps.

If you feel the rivet gun “jump” or the rivet feels loose after the mandrel snaps, the hole was likely drilled too large. Always test your fit on a scrap piece of metal before drilling into your final project piece.

Common challenges and how to fix them

Even experienced builders run into issues. One common problem is the mandrel not snapping off cleanly. This usually happens if you aren’t holding the rivet gun flush against the surface, or if you aren’t using enough force during the final squeeze.

If you find that your rivets are pulling through the hole, your material might be too thin. In these cases, use a backup washer (also known as a fender washer) on the backside of the rivet to increase the surface area and distribute the clamping force more effectively.

If you make a mistake, don’t worry. You can easily remove a set rivet by drilling through the center of the rivet head with a bit the same size as the original hole. The head will pop off, and you can then punch the remaining body out of the hole.

Frequently Asked Questions About how do pop rivets work

Do I need to prime or paint the rivet after installation?

If you are working on a project that will be exposed to the elements, it is good practice to apply a small dab of paint or sealant over the rivet head. This prevents moisture from entering the joint and helps the rivet blend into the finish of your project.

Can I use pop rivets to join wood to metal?

Yes, you can, but use a large-flange rivet. The wider head prevents the rivet from pulling into the softer wood fiber. Just be aware that wood expands and contracts with humidity, which can loosen the joint over time.

How do I know which size rivet to buy?

Check the packaging for the “grip range” and diameter. Most DIY projects use 1/8-inch or 3/16-inch diameter rivets. Always ensure the grip range encompasses the combined thickness of the materials you are fastening.

Is it possible to use pop rivets for structural repairs?

Pop rivets are excellent for holding parts in position, but they are generally not rated for heavy structural loads like a bolt or a weld. For critical safety components, always consult engineering guidelines or use high-strength hardware.

Mastering the craft

Now that you have a clear understanding of how do pop rivets work, you have a powerful tool in your belt for everything from fixing a leaky gutter to building custom cabinets. Remember, the key to great results is preparation—take your time measuring, drilling, and deburring your holes.

Don’t be afraid to experiment with different materials and thicknesses on scrap metal first. The more you practice, the more intuitive the process becomes, and soon you’ll be reaching for your rivet gun as naturally as you reach for a screwdriver.

Keep your tools clean, stay safe, and keep building. If you have any questions about specific projects or need advice on tool selection, feel free to drop a comment below. Happy making!

Jim Boslice
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