Locks use a mechanism that allows them to be opened by keys. This same mechanism allows them to be picked by burglars. Instead of replacing the key, a person can also match a lock with a key by taking the lock apart and switching out a few of its components. This is usually done by a trained locksmith, but it can be done by anyone with the right technical knowledge.
Things You'll Need
- Set of pins
Take the lock apart until you are able to take out the pins and tumblers. The lock will have screws visible on the inside of the door or on the thin side of the door when it is opened. The pins and tumblers look like small springs and metal pins, and the lock opens when they are properly aligned. Use a screwdriver to take the screws out first, and then the lock can be disassembled by hand. You might want to make a drawing that shows where all of the pieces go, so that you are able to place them back together when done.
Take the key, a new set of pins, and a ruler. Lay down the ruler so that it is parallel with the key, and lay down the pins against the notches of the key so that they fit the grooves of the key but lay flat against the ruler. Each key has different grooves, and the only way to match a lock with a key is by matching up the grooves. Note the order of the pins as they are arranged from the head of the key to its tip. This works only with tumbler locks, as others will need keys to be fitted for them instead.
Place the pins and the springs back into the lock in the exact order that you had them matched up against the key's grooves, and reassemble the lock to complete the task.