Deadbolt

A deadbolt or deadlock, is a locking mechanism, providing more security than an ordinary key-operated lock because the weight of the locking bar is usually sufficient to increase break-in time to 10 or 15 minutes.Fact|date=June 2007

Unlike most spring-bolt locks, in which the bolt is held in place only by the pressure of a spring and can easily be retracted, a deadbolt lock cannot be opened except by rotating the lock cylinder.

A variant of the standard deadbolt is the vertical deadbolt, which generally rests on top of a door. Vertical deadbolts resist jimmying (in which an intruder inserts a pry bar between the door and the frame and tries to pry the bolt out of the jamb).

Common Types

* Single Cylinder
* Double Cylinder
* Single Cylinder with removable thumbturn
* Classroom Function (thumbturn only unlocks door)
* Exit Only Function (no external cylinder)
* Pushbutton Deadbolt (mechanical or electrical)

Security Features

Many designs are available from manufacturers. Various manufacturers have patented designs offering unique solutions to prevent the locks from being defeated by picking, lock bumping, prying, and other forceful attacks.

See also

* Door security
* Lock bumping

External links

* [http://www.typesoflocks.com/locking-up-tight-with-a-deadbolt.php Locking up tight with a deadbolt]
* [http://www.opera-italy.com/english/solenoid_bolt_external_gate.html Deadbolt in a residential use]