This refers to the lock component where the key is inserted. A typical door knob has one keyhole, therefore one cylinder. Deadbolt locks are available in single-cylinder models and double-cylinder models. A double-cylinder model is operated from both sides with key, while a single-cylinder model uses a key from the outside and has a thumb-turn knob on the inside. Labor charges for rekeying locks is generally per cylinder. Therefore, if a door has a locking door knob and a double-cylinder deadbolt, there are 3 cylinders for the locksmith to service. If you are scheduling rekeying service, it is very helpful to have an accurate cylinder count. This allows us to provide an accurate cost estimate and to schedule ample time for the technician to complete the project.Cylindrical Lock
This refers to the most common type of modern lockset. The installation involves (among other things) boring a large hole all the way through the door. Most key-in-knob, key-in-lever, and deadbolt locks fall into this category.Deadbolt
This term can refer to an entire lockset or to one lock component. A deadbolt is a locking device that, once fully extended, cannot be retracted except by operating the locking device (usually a key cylinder or thumb-turn knob). It cannot be “jimmied,” “shimmed” or pushed back.Deadlatch
This is a lock component that can be part of any locking device that latches as the door closes. In addition to the primary triangular piece that catches the door frame, it has an extra component that prevents “shimming” the latch open with a credit card or pocket knife once it is closed. If door and frame alignment are incorrect or the lock is not installed properly, the lock does not have this added security feature. This is a common problem when locks are installed by anyone other than a professional locksmith. Security breaches or lock failures are a common result of improperly installed deadlatches. See also strike.Door prep
This refers to the hole pattern pre-cut into many new doors. ANSI has assigned numbers to many standard configurations. If you need hardware for a pre-drilled door, just tell the locksmith the ANSI number and we will know the door thickness, bore size, backset, and other relevant measurements to match you with the right hardware.