The most common type of deadbolt lock is known as a pin-and-tumbler, which uses pins of different lengths that only fit a specific key. You will find this type of lock inside a single cylinder deadbolt, which is found on most deadbolt doors. A single cylinder deadbolt has a keyhole on one side and a knob on the other. The lock itself sits inside the door. The less common double cylinder deadbolt has a lock on both sides of the door, but the inside of the lock works the same way.
Without the correct key, the deadbolt won't open. There are, however, some useful tips on ways to unlock a deadbolt if you lock yourself out of your home or lose your key.
Pick the Lock Using Bobby Pins
One of the best-known ways to unlock a deadbolt without a key is by using two bobby pins. Start by inserting the closed "looped" side of one bobby pin into the bottom portion of the lock. Use the second bobby pin, broken in half, toward the top of the lock and move it back and forth. This motion should set the pins and cause the deadbolt to unlock. If this doesn't happen within a couple of minutes, you should remove the first bobby pin and reinsert it before trying further.
If you do not have bobby pins on hand, you can use any small, thin piece of metal. You could try using a heavy duty paper clip, for example.
Bump the Lock Using a "Bump Key"
"Lock bumping" has been used to open deadbolts without a key for years. You can buy a bump key set from various locations including Lowe's and Walmart. Simply enter the bump key into the deadbolt lock and use a screwdriver or other sturdy-ended tool to hit the end of the key toward the door. The force should cause the key to turn, thus unlocking the door.
Unfortunately, this is also a way that many homes get broken into because this technique doesn't leave behind any signs of forced entry. This means that someone could break into your home using a bump key and you might never know it.
If you open the door using the bumping method, you should replace the lock. Although it's not always necessary, bumping a lock can damage the inside mechanism and cause further problems when it comes to unlocking the deadbolt using its original key.