Can a Broken Key Be Copied?
A broken key can often be reproduced, but the result depends on how much of the original remains, how worn it was before breaking and whether the correct blank is available.
Bring every piece of the key
Do not file, glue or reshape the fragments. Keep both pieces together and note which lock the key operated. A complete shoulder, tip and cut pattern gives the locksmith more information than a single damaged fragment.
How a replacement may be made
A locksmith may read the intact cuts, decode the lock, use an available key code or produce a key from another working original. Copying the wear of an old key exactly is not always desirable; the new key must match the lock rather than reproduce damage.
House keys, restricted keys and car keys
Common house keys are often straightforward when the blank is available. Restricted or high-security keys may require identification and authorization. Vehicle keys can also require a transponder chip, remote or programming, so a metal copy alone may not start the car.
When the lock also needs attention
If the key broke because the lock binds, making another key does not solve the cause. Stop using force and have the cylinder, latch and door alignment checked. A fragment left inside the lock should be removed before another key is tested.
For a house key, see residential key copying. For a vehicle, start with car key duplication and provide the make, model and year.