Riveting sheet metal comes down to drilling a correctly sized hole, inserting a blind rivet, and pulling the mandrel until it snaps. The process is simple enough for a first-timer to learn in minutes, but getting clean, strong joints depends on choosing the right rivet size, matching materials to avoid corrosion, and prepping each hole properly. Here’s how to do it right.
How Blind Rivets Work
A blind rivet (sometimes called a pop rivet) is a two-piece fastener: a hollow rivet body and a thin steel pin called a mandrel that runs through the center. You insert the rivet through a hole in your stacked sheets, then use a rivet tool to pull the mandrel backward. As the mandrel pulls through, it mushrooms the back side of the rivet body outward, clamping the sheets together. Once enough force builds up, the mandrel snaps at a preset breaking point, leaving a permanent mechanical joint.
Blind rivets are the standard choice for sheet metal work because you only need access to one side of the material. That makes them ideal for joining panels, brackets, ductwork, enclosures, and repairs where you can’t reach behind the workpiece with a wrench or welding torch.
Choose the Right Rivet Size
Rivet sizing has two critical dimensions: diameter and grip range. The diameter is the width of the rivet body, and the grip range is the total thickness of material the rivet can clamp. Getting either one wrong means a weak or failed joint.
Rivet trade sizes use a two-number code. The first number is the rivet diameter in 32nds of an inch, and the second is the maximum grip length in 16ths of an inch. A size 45 rivet, for example, has a 4/32-inch (1/8-inch) diameter body and a maximum grip range of 5/16 inch. When you see a rivet listed as “1/8-inch diameter, 1/4 to 5/16 inch,” that means it works for stacked material thicknesses between 1/4 inch and 5/16 inch.
To pick the right rivet, stack the pieces you’re joining and measure their combined thickness. That measurement must fall within the rivet’s grip range. If the stack is thicker than the maximum grip, the rivet won’t mushroom properly on the back side. If it’s thinner than the minimum, the rivet body will be too long and the joint will be loose. The maximum grip range is not the same as the rivet body length, so don’t confuse the two.
For most general sheet metal work, 1/8-inch diameter rivets handle light-duty joins. Step up to 5/32-inch or 3/16-inch diameter rivets when you need more shear strength or you’re fastening thicker or heavier-gauge material.
Match Rivet Material to Your Sheet Metal
Using the wrong rivet material with your sheet metal creates galvanic corrosion, a chemical reaction that eats away at the metals wherever moisture is present. The further apart two metals sit on the galvanic series (a ranking of metals by electrical potential), the faster they corrode each other. Fastener locations are the most common spot for this kind of damage.
Aluminum rivets in aluminum sheet metal are the safest pairing. Steel rivets in aluminum panels, on the other hand, will corrode aggressively over time, especially outdoors. If you must use dissimilar metals, apply a sealant or barrier compound to the rivet and the hole before setting it. This “wet installation” blocks moisture from reaching the metal-to-metal contact point. For any joint exposed to rain, humidity, or salt air, matching your rivet alloy to your sheet metal is the simplest way to avoid problems.
Stainless steel rivets paired with stainless steel or galvanized sheet metal work well for outdoor and marine applications. Aluminum rivets with steel mandrels are common in hardware stores; they’re fine for interior or protected work, but the steel mandrel stub left inside the rivet can eventually rust if exposed to weather.
Tools You’ll Need
A manual hand riveter is the most affordable option and the right choice for small projects, repairs, or occasional use. You squeeze the handles to pull the mandrel, and the rivet sets. It requires no power source and costs roughly $15 to $40 for a decent model. The trade-off is hand fatigue: setting large rivets or driving dozens in a row gets tiring quickly, and the physical effort increases with rivet diameter.
Battery-powered rivet tools eliminate the fatigue entirely. A motor pulls the mandrel and forms the rivet in seconds with no physical exertion from you. These tools pay for themselves on larger projects where you’re setting many rivets in a session. They typically run $80 to $200 for a good cordless model, and they’re noticeably faster and more consistent than manual squeezers.
Pneumatic (air-powered) rivet guns are built for heavy daily use in production environments. Unless you already have a shop compressor and you’re riveting sheet metal all day, a hand tool or cordless tool will cover most needs.
Beyond the rivet tool itself, you’ll need a drill (cordless or corded), the correct drill bit for your rivet diameter, a center punch, a tape measure, a marker or scribe, and a deburring tool or fine file.
Drill Bit Sizes for Standard Rivets
The hole needs to be just slightly larger than the rivet body so the rivet slides in without force but doesn’t wobble around. A hole that’s too tight won’t accept the rivet; a hole that’s too loose produces a weak joint with play in it. The ideal clearance is about 0.1 mm (roughly 0.004 inches) larger than the rivet diameter.
Here are the standard pairings:
- 1/8-inch rivet: Use a #31 drill bit
- 5/32-inch rivet: Use a #21 drill bit
- 3/16-inch rivet: Use a #13 drill bit
Numbered drill bits are sold individually or in sets at any hardware store. If you don’t have the exact numbered bit, a fractional bit one size up from the rivet diameter will usually work, but the numbered bits give you the tightest, cleanest fit.
Prepare the Sheet Metal
Clamp or hold the two pieces of sheet metal together exactly where you want them joined. Mark your rivet locations with a center punch. The punch dimple keeps the drill bit from wandering across the metal surface when you start drilling.
Drill through both layers at once whenever possible. This ensures the holes align perfectly. Run the drill at a moderate speed and let the bit do the work rather than forcing it through. Sheet metal is thin, so the bit will break through quickly.
After drilling, check that each hole is clean and free of burrs. Sheet metal tends to leave a sharp lip of raised material around the exit side of the hole. Remove burrs with a deburring tool, a countersink bit spun lightly by hand, or a fine file. Burrs prevent the rivet flange from sitting flat against the surface, which weakens the joint and looks sloppy.
Set the Rivets
Load the rivet into the hole from the front side (the side you’re working from). The rivet’s factory flange, the flat disc at the top, should sit flush against the surface of the sheet metal. If it’s sitting up on a burr or not going through the hole easily, pull it back out and clean up the hole.
Slide the mandrel tail into the nose of your rivet tool. The nosepiece on most tools is sized for a specific rivet diameter, so swap to the correct nosepiece if needed. Hold the tool straight and perpendicular to the surface. Angling the tool while pulling will deform the rivet unevenly and weaken the connection.
Squeeze the handle (or press the trigger on a powered tool). You’ll feel resistance build as the mandrel pulls the back side of the rivet into a mushroom shape against the far side of the sheet metal. On a hand tool, you may need two or three full squeezes. The mandrel will snap with an audible pop when the joint is fully formed.
After each rivet, check the connection. The flange on the front should be tight against the surface with no gap. On the back side, if accessible, look for a uniform, symmetrical bulge. If the rivet spins in the hole or the sheets still move relative to each other, the rivet is undersized or the hole was too large. Drill it out and go up one rivet diameter.
Spacing and Layout
Place rivets at least three rivet diameters from the edge of the sheet to avoid tearing. For a 1/8-inch rivet, that means keeping the hole center at least 3/8 inch from the edge. Space rivets apart by roughly three to six rivet diameters, depending on how much load the joint needs to carry. Closer spacing gives more strength but takes more time and rivets. For non-structural panels and enclosures, spacing rivets every 1 to 2 inches along a seam is typical.
When joining a long seam, set a rivet at each end first to lock the alignment, then fill in the middle. This prevents the sheets from shifting as you work your way across.
Removing a Bad Rivet
If a rivet sets poorly or you need to disassemble later, drill it out. Use a drill bit the same diameter as the original rivet hole and drill straight down through the center of the rivet head. Go slowly. Once you’ve drilled through the flange, the rivet body will push out or fall free from the back side. Clean up the hole, and you can set a new rivet in the same spot as long as the hole hasn’t been enlarged significantly. If it has, step up to the next rivet diameter.