Get a broken key out of a lock
A key usually snaps when it's worn thin or someone forces a stiff lock. The good news is that a broken piece usually comes out with simple tools, as long as the lock is back in the position the key went in and you don't push the piece deeper. A dry lubricant and a thin hooked tool do most of the work. If the piece is stuck while the lock is turned, or nothing will grab it, a locksmith can remove it, often without damaging the lock.
Why a broken key gets stuck
Most house locks are pin tumbler locks. The part the key goes into is a cylinder called the plug, and above it sit stacks of small spring-loaded pins. The notches on a key lift each pin stack to just the right height so the plug can turn. When the key breaks, the piece left inside still has those notches, and the springs push the pins down onto them. That pressure, plus any dirt or wear, is what holds the piece in place.
A key can only come out when the plug is in its home position, the same position it was in when the key went in. If the key snapped while you were turning it, the plug may be stuck partway, and nothing will slide out until it's turned back. Pushing on the broken end, or trying to use the lock, can jam the piece behind the pins, and glue on a stick or matchstick tends to end up inside the lock. Work gently, keep the piece moving outward and stop if it's going deeper.
Why keys break in locks
Years of use thin the neck where the blade meets the head.
Dirt or a misaligned bolt makes you twist hard, and the key gives first.
Poorly cut duplicates bind on the pins and snap.
Pulling the door shut by the key bends it over time.
A key that almost fits can jam and break when turned.
| You notice | Likely cause | Start at |
|---|---|---|
| Key broke while the lock was turned | Plug is out of home position | Step 1 |
| Piece is stuck tight, lock feels gritty | Dirt or dry pins | Step 2 |
| Part of the key sticks out | Easy grab | Step 3 |
| Piece is flush or inside the keyway | Needs a hook tool | Step 4 |
| Nothing grabs it, door secured from inside | Remove the cylinder | Step 5 |
| The lock was stiff before it broke | Lock needs attention | Step 6 |
Let's fix it
- Stop and turn the lock back to homeLook at the keyway. If the slot is straight up and down (or in the same position as when you put the key in), the plug is home and you can move on. If the key broke while it was turned, the plug is probably stuck partway. If a stub sticks out, grip it with needle-nose pliers and gently turn it back to the starting position. If nothing sticks out, a flat tension tool or a very small flat screwdriver, used gently slid into the empty part of the keyway can sometimes turn it back, but stop if it doesn't move easily. Forcing it can push the piece deeper, and that's the point to call a locksmith.
- Spray in a dry lubricantUse a tube of graphite powder or a can of dry PTFE (Teflon) lock lubricant with its thin straw and give the keyway 1 or 2 short puffs, aiming along the top and bottom of the broken piece. Wait about 1 minute. The lubricant eases the pins' grip on the key and helps the piece slide. Avoid oily products like cooking oil, and use only a little of any spray, since too much attracts dirt. If you have nothing else, a tiny amount of general-purpose lubricant will do in a pinch, but plan to clean and dry-lube the lock afterward.
- Grab any part that sticks outIf even a little of the key shows past the face of the lock, grip it with needle-nose pliers or sturdy tweezers, as close to the lock face as you can. Keep the pliers in line with the keyway and pull straight out while wiggling gently up and down, not side to side. Don't squeeze so hard that the soft brass flattens and slips. If it moves a little and stops, add another puff of lubricant and try again. Most stubs come out this way.
- Hook a flush piece with an extractor or bladeIf the piece is flush or recessed, use a broken key extractor (a thin steel strip with small hooks or barbs, sold at hardware stores in sets for about $10 to $15). Slide it into the keyway along the top edge of the key, where the notches are, with the hooks facing out toward you. Push it in as far as the key goes, turn it slightly so a hook bites into a notch, and pull straight out. It often takes several tries, working along the top and then the bottom. A thin, narrow jigsaw blade with its teeth angled back toward you works the same way. If it's too wide, snap it narrower with pliers while wearing safety glasses and gloves, since pieces can fly.
- Take the cylinder to a locksmith if it won't budgeIf nothing grabs the piece and you can work from inside, you can remove a typical deadbolt without damaging it. With the door open, unscrew the two long screws on the inside thumb-turn plate and pull both halves of the lock off the door. Bring the outside half, with the key piece still in it, to a locksmith or a hardware store that rekeys locks. They can take the cylinder apart on the bench and remove the piece, usually for less than a house call. Don't take the cylinder apart yourself unless you know how: the pins and springs pop out and have to go back in a specific order.
- Test the lock and get a new keyOnce the piece is out, try a spare key, not the broken one. It should go in smoothly and turn without forcing. If it's stiff or gritty, puff in a little more dry lubricant and work the key in and out a few times, or follow the guide for a sticking deadbolt. Throw away the broken key and have a new one cut from a good original, not a worn copy, since copies of copies wear the lock faster and break again. If you have no spare, a locksmith can often cut a key from the broken pieces or rekey the lock.
Watch it done
- The keyway is empty and you can see the lock face clearly
- A spare key goes in and turns smoothly
- The bolt locks and unlocks without forcing
If it comes back
A second broken key usually means the lock is fighting you. If you have to lean on the key or lift the door to turn it, the bolt is rubbing on the strike plate. See the guide for a sticking deadbolt and the guide for a door that sticks or won't latch.
If the knob or lever wobbles while you use the key, tighten it first, since a loose lockset puts side load on the key. See the guide for a loose door knob.
If the lock is old and worn, or you've lost track of who has keys, it may be time to rekey or replace it. A rekeyable lock or a locksmith visit lets you keep the hardware and change the key.
What a pro typically charges (a rough estimate; prices vary by area): A locksmith typically charges about $75–$150 to remove a broken key at your home, and more after hours. Bringing the cylinder to a shop often costs less, and rekeying usually adds about $20–$50 per lock.
Find a locksmith near you