Re-keying is the process of replacing the tumblers or pins of a lock cylinder with new ones of different sizes. Upon completion, a new key is required to operate the lock. If the lock functions well and matches the style you like, then re-keying is the best solution. This service saves money and time by eliminating the need to buy and install a new deadbolt or door knob lock. Locks should be re-keyed when first moving into a property or when a set of keys is lost.