Deadbolts are door security devices that have an elongated bolt that, when engaged, will insert into the door jamb to provide protection from forced entry. They are an inexpensive option for home security. Deadbolts are stronger and more resistant to pressure and force than conventional door locks. Conventional locks can break easily and are relatively easy to tamper with.
Deadbolts prevent a door from being forced open. The lock consists of one or more cylinders which are connected to a latch. A metal bolt is used to create a firm and secure lock when moved into a hole in the strike plate of the door. They can be actuated by key on one or both sides as well as by a lock mechanism which rotates to move the bolt.
A deadbolt has three main components.
A cylinder is the part of the lock that the key will be inserted into to work the lock. A tapered cylinder is much safer than a non-tapered cylinder.
Bolt refers to the metal component that secures the door to the door frame. The bolt should be made of a strong metal such as reinforced steel and the length of the bolt should extend at least one inch past the edge of the door when locked.
A strike plate is a metal piece that fits into the door frame. The strike plates reinforces the bolt by preventing the bolt from ripping through the door frame if the door is forced open. For the highest security, make sure that the strike plate is aligned with the deadbolt in the door and the screws into the door frame are longer than 1 1/2 inch.
Deadbolt valve components. Image Credit: Mul-t-lock-online.com
There are two types of deadbolts to select. Depending on the application, users may want to purchase an internal deadbolt or a surface mounted deadbolt.
Internal deadbolt- Internal deadbolts are somewhat difficult to install but they offer superior security from thieves and intruders. An internal deadbolt is mounted inside the door so that the bolt goes into the strike in the door. The outside of the door is a key or combination lock and there is a latch on the inside. This design makes it difficult for intruders to dismantle the lock.
Surface mount lock- Surface mount locks are very easy to install and are best used for privacy or to keep someone (i.e. children) venturing where they shouldn't. A surface mount lock attaches the door to the door frame (door jamb) with a sliding bolt. The outside of the door has a key entry lock and the deadbolt lock on the inside. When using the key entry lock, the key would pull or lift the bolt from the bolt case to open the door. The inside deadbolt is operated with a latch. There are two models available: two cylinders and rim or jamb models. Surface mount deadbolt locks are also referred to a night latches.
Two types of deadbolt locks. Image Credit: easy2diy.com