Snapped or Broken Key in the Lock? What to Do

Short answer: stop turning or pushing. If part of the key is sticking out, try to pull it straight out with fine-nosed pliers or tweezers. If it's flush or below the surface, don't dig at it, as that pushes it deeper. Call a locksmith, who can extract it and cut a new key, often from the broken pieces.

Why keys snap

Keys rarely break for no reason. The usual causes:

A worn key. Years of use thin the metal at the shoulder.
A stiff lock. Dirt, corrosion (common near the coast) or a worn cylinder makes the key work harder.
Force. Using the key as a handle to pull the door, or turning it too hard when it sticks.
A cheap copy. Soft metal or a badly cut duplicate.

What to try

If part of the key is still sticking out:

Make sure the lock is in the position where the key went in (usually vertical). The key can only come out in that position.
Grip the end with fine-nosed pliers or strong tweezers.
Pull straight out, gently, without twisting.

What not to do

Don't push the other half of the key in to try to turn the lock.
Don't use superglue on a stick or the broken half. It can glue the lock shut.
Don't keep poking with a pin or screwdriver. It pushes the broken piece deeper and can damage the pins.

How a locksmith fixes it

A locksmith uses thin extraction tools that hook the key's cuts and slide it out without damaging the lock. Once it's out, they can:

Cut a new key from the broken pieces, from the lock itself, or to the original key code
Service the lock if it's stiff or corroded, so the new key doesn't snap too
Replace the cylinder if the lock is worn out

If the door is locked and you can't get in, the locksmith will open it first. See emergency lockouts.

Snapped in the car?

If the key broke in the car door or ignition, you'll need an automotive locksmith, because car keys have chips that need programming. See key stuck in the ignition and car key replacement.

How to stop it happening again

Replace worn keys before they break. A key cut to the original code is better than a copy of a worn key.
Lubricate stiff locks with a lock lubricant (dry graphite or silicone), especially near the beach where salt air corrodes locks.
Don't pull the door with the key.
Get a stiff lock looked at rather than forcing it.

Your questions, answered

How do you get a broken key out of a lock?

If part is sticking out, pull it straight out with fine-nosed pliers. If it's flush with the lock, call a locksmith, who uses extraction tools.

Can a locksmith make a new key from a broken one?

Usually, yes. The two halves can be lined up and copied, or a key can be cut from the lock.

Will the lock need replacing?

Not usually. Most locks work normally once the broken piece is removed. A worn or damaged cylinder may need replacing.

Why did my key snap?

Usually because the key was worn, the lock was stiff, or too much force was used. Fix the cause or the new key may break too.

Is it safe to use WD-40 on a lock?

Lock-specific lubricants such as dry graphite or silicone are better. Oily sprays can attract dust and grit.