Reviewed by Emergency Locksmith NY|Published: | Updated:
Do Not Panic -- and Do Not Push It Further In
A key breaking inside a lock is startling, but it is a common problem that locksmiths handle routinely. The most important thing to know: do not try to push the broken piece further into the lock or try to turn it with pliers. Both actions can push the fragment deeper, making extraction harder, or damage the internal mechanism.
Why Keys Break
Worn keys: Over time, the metal of a frequently used key develops hairline fractures, especially at the thinnest cut points. One day, the force of turning is enough to snap it.
Worn lock: A lock with internal wear forces you to use more turning pressure, which increases stress on the key. If you have noticed your key getting harder to turn, that extra force is a recipe for a break.
Cold weather: Metal contracts in cold temperatures. NYC winters can make both keys and lock mechanisms more brittle and less forgiving.
Cheap key copies: Keys cut on low-quality blanks at hardware stores are more prone to breaking than keys cut on proper branded blanks by a professional locksmith.
Excessive force: Turning a key too hard, especially while jiggling or wiggling to overcome a stiff lock, is the most common cause of breakage.
What to Try First
If part of the key is sticking out of the lock, you may be able to extract it yourself with needle-nose pliers. Grip the exposed end firmly and pull straight out. Do not twist. If the fragment is flush with or inside the keyway, do not attempt to dig it out with a screwdriver or wire -- you will almost certainly push it deeper or damage the pins.
Professional Broken Key Extraction
A locksmith uses specialized extraction tools -- thin, hooked blades designed to slide alongside the broken fragment and pull it out of the keyway. The process is typically quick (5 to 15 minutes) and non-destructive to the lock. In most cases, the lock continues to function normally after extraction.
If the fragment has been pushed deep into the cylinder or the lock mechanism has been damaged by DIY extraction attempts, the locksmith may need to remove the entire cylinder for better access. In rare cases where the fragment is lodged behind the pins, disassembly of the cylinder is required.
After the Key Is Extracted
Test the lock: The locksmith will test the lock with a working key (or pick it open) to confirm the mechanism was not damaged.
Inspect the lock: If the key broke because the lock is worn, stiff, or corroded, this is a good time to discuss rekeying or replacement.
Replace worn keys: If the broken key was visibly worn, have new copies cut from a fresh original (not copies of copies, which degrade over generations).
Preventing Key Breakage
If the lock is stiff, apply graphite lubricant rather than forcing the key
Replace visibly worn keys before they break -- if you can see shiny spots or bending along the shaft, it is time for a new copy
Do not use your key as a tool (prying, opening packages) -- this weakens the metal
In most cases, no. Professional extraction removes the fragment without damaging the internal mechanism. However, if someone has tried to dig out the fragment with tools like screwdrivers or wires before calling a locksmith, the pins or cylinder may be scratched or dented, potentially requiring rekeying or replacement.
How much does broken key extraction cost?
Broken key extraction alone typically costs $50 to $125 in NYC, depending on the difficulty and time of day. If you also need a new key cut (because the broken key was your only copy), add the cost of key cutting or rekeying.
Should I replace the lock after a key breaks in it?
Not necessarily. If the key broke due to wear or cold and the lock itself is in good condition, extraction plus a new key is sufficient. If the key broke because the lock mechanism is worn and requiring excessive force, that is a sign the lock should be replaced to prevent the same problem from recurring.
