At some point, you might need to open a deadbolt lock but won't be able to find the key. Although the deadbolt is strong, the lock itself usually is not complicated. You can use one of two main strategies for unlocking a deadbolt lock without the key--picking and bumping.
Picking a Lock
Picking a lock is the act of unlocking the device with tools to mimic the actions of the key. Most deadbolt locks have standard five-pin cylinders--the same as ordinary spring-bolt locks on a door knob.
You need two tools to pick a lock--a torque tool and a pick tool. Both can be made from a strong, flat, thin piece of metal such as a street-sweeper bristle.
Before picking a lock, make sure no obstructions in the keyhole would prevent insertion of the tools. An obstructed keyhole cannot be picked. Insert the torque tool in the lower half of the keyhole and twist it gently to one side as if you were opening the lock with a key. Run the pick tool slowly back and forth along the top half of the keyhole until the lock opens.
Bumping a Lock
To bump a lock is to insert a special key into the lock and shake, or bump, it until the locking mechanism is triggered and unlocks. The bumping key is in the same shape as the lock's normal key but with the teeth filed down.
Once the bumper key has been inserted into the lock, the best method is to hit the key firmly on its top. The force of the hit should be strong enough to jounce the key upward and trigger the lock but not so strong as to break the key.
Bumping, performed improperly, can damage the lock or cause the bumping key to get stuck inside it. Bumping keys should be made of the hardest material possible to prevent it from going too deep into the lock and becoming irretrievable.