Stripped or Snapped Screw? Rescue Methods That Actually Work
Six proven ways to extract a stripped, rusted, or snapped-off screw without destroying the host material. Pick the right method by situation — rubber band, extractor bit, left-hand drill, plug-cutter.
Identify the problem first
- Stripped head — the bit spins in the recess. Most common, easiest to rescue.
- Snapped flush with the surface — recess is gone but threads are intact.
- Snapped below the surface — head is gone and a stump remains in the host material.
- Rusted / seized — head intact but the screw will not turn.
Stripped head — the rubber band trick
Place a rubber band (a wide elastic band works best) flat over the screw head, press the driver bit firmly through it into the recess, and turn slowly. The rubber fills the gaps in the chewed-up recess and gives the bit enough grip to back the screw out. Cost: free. Works on about 60% of stripped heads.
Stripped head, no luck with the band — screw extractor bits
A screw extractor set (around £12–£25 for a 5-piece) has reverse-cutting bits. You drill a small pilot into the screw head, then switch to reverse and the extractor bit grips and backs the screw out. Always use a low-speed drill setting and back the trigger off the instant it grips — high RPM snaps the extractor inside the screw, which is a worse problem.
Snapped flush — drill out, retap, replace
If the screw is flush with the host but threads are intact in the host:
- Centre-punch the snapped screw face. This stops the drill bit wandering.
- Drill straight down with a left-handed drill bit (same diameter as the screw core). Often the reverse rotation backs the screw out before you finish drilling.
- If it does not back out, drill all the way through, clean the threads with a tap of the original size, and replace with a new screw.
Snapped below the surface — plug and replace
When the screw has snapped below the host surface (common in old timber where the head has rusted off), drill the snapped stump out with a plug cutter, fill the hole with a glued dowel matching the host, sand flush, and re-drill a pilot for a fresh screw. Takes 20 minutes per fixing but leaves an invisible repair. The plug cutter — £8–£15 — is the only specific tool you need.
Rusted / seized — heat and penetrating oil
Spray with a proper penetrating oil (Plus Gas, not WD-40 — WD-40 is a water-displacer, not a penetrant). Leave 10 minutes. Apply heat with a small butane torch for 20 seconds (avoid in flammable cavities) — the differential expansion breaks the rust bond. Tap the head firmly with a hammer to send shock through the threads, then attempt to back it out.
Prevention beats rescue — use an impact driver
Most stripped screws are caused by a regular drill-driver wallowing in the recess on tight fixings. An impact driver — distinct from a hammer drill — delivers rotational hammer blows that drive the bit deep into the screw recess every impact, so it never cams out. For deck-screws, ledger boards or anything bigger than a 5mm woodscrew, an impact driver is the right tool. Day rental £8–£15 on DIY Toolshare.
Frequently asked questions
Why does my drill keep stripping screw heads?
Usually one of three things: wrong-sized bit for the screw recess (a PH2 in a PZ2 screw, or vice versa), too high a torque setting on a drill-driver, or cam-out from a worn bit. Match the bit to the head type exactly, use a clutch setting under 8 for woodscrews, and replace bits when the tip rounds off.
Are screw extractor bits reusable?
A good set takes 20–40 extractions before the bit teeth wear. Cheap eBay sets often snap on the second use, which is worse than starting with no extractor — you then have hardened steel inside the screw inside the host.
Will WD-40 free a rusted screw?
WD-40 is a water-displacer. It will lubricate the bit-to-head interface but does not actually penetrate corrosion. Use a proper penetrating oil (Plus Gas, PB Blaster, or similar) and give it 10 minutes to work.