A door bolt is a type of security lock. They are often used on home entrances or any other doors that need additional security. There are several types of door bolts, including the deadbolt, spring lock, mortise lock, and slide bolt. Keyless bolts and night latches are also popular, particularly for commercial settings.
A deadbolt lock is considered by many to be the most secure type of door bolt. This particular kind of bolt has both a male and female part. The male part, or cylinder, contains a metal rod that is operated by either a thumb latch, key, or both depending upon the style. This part is generally embedded into the edge of the door. The female housing for the metal rod is inserted into the doorframe so that, when the bolt is operated, the rod slides firmly into the housing and secures the door to the doorframe.
Another type of door bolt, often referred to as a spring latch, is similar in style to a deadbolt. The primary difference is that the deadbolt is not operated by a spring mechanism, whereas the spring latch is. This fact causes many to feel that the spring latch provides inferior security because the spring mechanism can be manipulated and pried open by someone determined to gain unauthorized entry.
The type of bolt known as the mortise lock is actually a type of deadbolt. It is also mounted directly into the door and frame and latches the door to the frame with the use of a sliding metal rod. This type of door bolt is normally operated by a key rather than a thumb latch. Quite often, it is part of the doorknob casing itself and is a very common type of door bolt for many residential houses and apartments.
Perhaps the least secure type of door bolt is the slide latch. This type of bolt is attached by screws to the surface of the door and the doorframe. It consists of a manually operated sliding bar that fits into the housing mounted on the doorframe. As this type of bolt is secured to the door and frame by screws, it can be forcibly ripped from the door by someone desiring unauthorized entry. Normally, it is used when only minimal security is required.
Some door bolts are specifically designed for the higher security needs of commercial structures. For instance, the night latch is a type of door bolt that locks automatically when a door is closed. This can be important in settings such as day care facilities when parents go in and out to pick up their children but do not have a key to lock the door after they leave the premises. Also, keyless deadbolts, which are operated by a specific code entered on an electronic keypad, provide a higher degree of security because there is no risk of a key being lost or stolen. While originally designed for commercial settings, keyless bolts are being used more and more in residential settings.