Stripped screw hole in sheet metal?

Last updated: July 17, 2026

A self-tapping screw that spins freely and won't tighten has stripped the few threads it cut — sheet metal gives a screw almost nothing to hold onto. First tell the two failures apart: a rounded screw head is a driver problem (fixed like on the wood side), a spinning hole means the metal threads are gone. For a stripped hole in thin sheet, the fixes that actually hold are go up a screw size, set a rivnut, or bolt through with a washer.

Which one is it? If the driver rounds the screw head and won’t grip, that’s a stripped head (cam-out) — the same problem as on the wood side, same fixes. If the screw spins freely and won’t pull tight, that’s a stripped hole: the sheet-metal threads are gone. Different problems, different fixes — the stripped hole is what this page is about.

Stripped a screw in wood, not sheet metal? That’s a different repair (toothpicks, dowels, glued plugs). See why your screw keeps stripping for the wood side; this page is the metal one.

Two failures people call “stripping”

Work out which you have before you fix anything. A stripped head is up top: the recess is rounded, and the driver spins inside it or slips out. A stripped hole is in the sheet: the head is fine, but the screw turns without tightening because the metal around the threads has given way. They feel similar — the screw won’t do what you want — but the causes and the fixes share nothing.

The head stripped (the driver rounds it out)

This is cam-out: the bit slips out of the recess under load and rounds it off, and it happens the same way in metal as in wood. The fixes are the same too — a fresh, correctly sized bit, firm pressure, lower speed, and a rubber band or a screw extractor to back out one that’s already rounded. The wood guide covers it in full, so rather than repeat it: how to fix and prevent a stripped screw head. The rest of this page is the failure that’s specific to sheet metal — the stripped hole.

The hole stripped: why sheet metal is different

Here the screw spins and never tightens because the threads it cut in the metal are gone. What makes sheet metal its own problem is depth: a screw in wood bites into fibre that runs deep, but a sheet gives it almost nothing — a 22-gauge sheet is a fraction of a millimetre thick, so the screw only ever held on two or three threads’ worth of metal. Wipe those out and there’s no reserve underneath to catch on. That’s why a stripped hole in sheet metal often can’t just be re-driven, and why the durable fixes add material or move to fresh metal.

What stripped it

• The pilot hole was too big. The most common cause, and it’s the site’s own subject: an oversized pilot leaves the threads nothing to bite. Size it right with the self-tapping screw pilot-hole tool.
• Over-tightening. In sheet metal the last quarter-turn after the screw snugs is what strips the few threads it has. Stop when it’s tight, not a beat later.
• Driving in and out. Removing and re-driving in the same spot reams the hole a little wider each time until nothing grips.
• The threads end before the head. On some self-tappers the thread runs out short of the head, so the screw drives in and then spins freely without ever snugging down. That reads as a stripped hole but isn’t — the screw is too long or the wrong type for how thin your stack-up is. A shorter screw, or one threaded all the way to the head, seats properly. Check this before you decide the hole is stripped.

The fixes, easiest first

Every one of these keeps you in the same job — drilling a hole for a fastener you buy. None of them cuts a new thread into the metal (that’s a different job; see the note below).

• Go up a screw size. The fastest fix. A larger-diameter or longer self-tapping screw bites metal the stripped one chewed past. It works when a bigger screw still suits the job and there’s sound sheet around the hole, and it holds about as well as the original did. You get a try or two before the hole’s too far gone.
• Set a rivnut (threaded insert). The proper fix when you need a real, reusable machine thread in thin sheet. A rivnut is a threaded sleeve that clamps the sheet from both sides and gives you a clean bolt thread the metal could never hold on its own. This is a drill-size question: drill the hole to the insert’s stated outside diameter (on the packaging), set it with the tool, then thread a bolt in. If the spec is metric and your bits are imperial, the drill bit size converter gives the nearest bit. Holds a real load — this is the structural-grade fix in thin material.
• Nut and bolt with a fender washer. If you can reach the back of the sheet, a bolt through the hole with a nut and a wide fender washer (or a backer plate) beats any screw-into-sheet repair. The washer spreads the load so it can’t pull back through. The strongest option when access allows.
• Relocate to fresh metal. When strength matters and the hole is beyond saving, move the fastener a short distance to sound metal. A fresh, correctly sized hole in good sheet holds better than any patch of a reamed-out one.
• Metal-reinforced epoxy — light duty only. A steel-filled epoxy putty packs a stripped hole and holds a screw once cured. Fine for a trim clip, a cover panel, a light bracket. It is not a structural repair and won’t take a real load or vibration. If the fastener does a job, use one of the fixes above.

What about re-tapping or a Helicoil?

Those cut a new thread into the metal itself — re-tapping to a larger thread, or a Helicoil-type insert that needs the hole tapped first. That’s thread-cutting, a different job with its own tools, and it’s beyond what this guide covers. In thin sheet it’s usually the wrong approach anyway: there isn’t enough material depth to tap a thread worth having, which is exactly why a rivnut or a bolt-through holds better. If you’re in thick plate and set on tapping, that’s a machining reference, not this one.

Preventing it next time

Three habits stop the repeat. Size the pilot correctly for the gauge and thickness — too big is the number-one cause, and the self-tapping screw pilot-hole tool gives the size. Don’t over-tighten: stop the driver when the screw snugs. And use the right screw for the thickness — a self-drilling (TEK) screw in thicker steel, a self-tapper in a properly sized pilot in thin sheet.