How to Use a Pop Rivet Gun | Strong Joints in 6 Steps

A pop rivet gun fastens materials by pulling a rivet’s mandrel until the body expands, then snaps the mandrel off — the whole process takes seconds once you follow the correct order.

A pop rivet gun creates permanent metal-to-metal joints that hold tight without welding or screws that could back out. The mechanism is simple: you load a rivet with its mandrel pointing into the gun, insert the body into a pre-drilled hole, then squeeze the handles. The mandrel is pulled through, expanding the rivet’s tail on the far side until the mandrel snaps — and you’ve got a solid fastener that won’t loosen by itself. The process works identically for manual hand tools and air-powered rivet guns, though manual tools require you to remove the broken mandrel after each set. If you’re shopping for a reliable tool, our tested pop rivet gun roundup covers the best options for different budgets and workloads.

What You Need Before Starting

Before you squeeze a trigger, you need three things sized correctly: the rivet, the drill bit, and the gun’s nosepiece. The rivet shank should be at least 1.5 times the thickness of both materials combined — if you’re joining two 1/16-inch sheets, you want a rivet with a shank length of about 3/16 inch or slightly longer. The drill bit needs to be roughly 1/64 inch larger than the rivet shank diameter, not the head size. And the gun’s nosepiece must match the rivet shank; most guns come with interchangeable nosepieces stored in the handle or a separate compartment.

Safety glasses and work gloves are mandatory for this job. The broken mandrel snaps off with enough force to hit your face, and the rivet edges can be sharp. Clamps or locking pliers to hold the workpieces together are also essential — movement during drilling or riveting produces weak, misaligned joints.

Drilling and Setup: The Step That Determines Success

The hole must be exactly where you need the rivet, because you can’t move a pop rivet after setting it. Clamp the two pieces together firmly, then drill straight through both at once using the drill bit you measured to the shank size. A pilot punch mark helps keep the bit from walking across the surface. Remove the burrs from both sides of the hole with a deburring tool or a larger bit turned by hand — a rough hole makes the rivet seat unevenly and reduces joint strength. If the parts shift during drilling, unclamp, realign, reclamp, and drill again.

How to Load and Set the Rivet

Insert the rivet into the gun’s nosepiece with the mandrel — the thin pin — going into the barrel first, not the rivet head. The head should be flush against the nosepiece face. Push the rivet body all the way into the drilled hole until the head sits flat against the workpiece surface. If the head doesn’t seat fully, the joint won’t clamp tight.

Single step sequence: Squeeze the handles firmly and steadily. The gun will pull the mandrel through the rivet body, expanding the blind side. Keep the gun perpendicular to the work and maintain steady pressure — jerking the handles can snap the mandrel early. After a few seconds, the mandrel will break with a pop sound. That pop confirms the rivet is set. In a manual gun, tip the tool downward so the broken mandrel falls out of the nosepiece; in a power gun, the tool usually captures it internally. Discard the mandrel — never leave it inside the gun or reuse it.

Common Mistakes and How to Fix Them

The three most frequent failures are the wrong rivet size, the wrong hole diameter, and the wrong nosepiece. Any one of these will prevent the rivet from setting properly, and you’ll end up with a loose joint where the mandrel either pulls through without expanding or jams in the gun. If the mandrel snaps too early before the rivet body expands, check that the rivet shank is long enough for your material stack and that the hole is the correct diameter. If the rivet body spins inside the hole when you squeeze, the hole is too big — drill the next size down or use a larger rivet diameter. Always verify that the head sits flush before you squeeze; an angled or partially inserted rivet produces a weak set that may fail under load.

After setting, inspect the back side of the joint. The expanded tail should form a uniform, button-like shape. If it looks flat or uneven, the rivet size was wrong or the gun wasn’t perpendicular.