How A Deadbolt Works

deadlock open in a door

Install a deadbolt on every external door to keep your home and family safe and secure. A deadbolt is reasonably priced, easy to install, and tough to break through. Read on to learn about different kinds of deadbolts and how they work to help determine which style is right for you.

Surface Mounted vs Internal Deadbolts

Internal deadbolts and surface-mounted deadbolts are used for home security. Between the two, surface-mounted models are easier to install but do not provide quite as much security.

Surface-mounted deadbolts attach the door to the jam with a sliding bolt. Most of these come in either 1 or 1 cylinders, and then in either rim or jamb styles. There might be a keyhole on the outside, or it can be flat with the deadbolt opening from the inside. You insert your key and turn it (or unlatch it with the deadbolt knob) to move the cylinder in place and lock the door.

An internal deadbolt is placed on the inside of the door. The strike goes inside the jamb of the door. The outside of the lock is either key entry or a combination lock. Once the proper key is punched in or the key is turned, the lock disengages. This type of device is particularly hard for an intruder to dismantle because the lock is located inside the home.

Cylinder Lock

When you insert a key into a cylinder lock deadbolt, you are turning the cam which, in turn, twists a plug. When this occurs, the bolt is either slid forward into the frame or pulled away back into the mechanism. Many locks work in the same manner, but using a spring instead of a solid structure.

Pins and Tumblers

Inside the cylinder are pins and tumblers. The pins vary in height and are always in pairs. Each pair of pins rest inside a tube that runs through the cylinder and around the plug. Springs are positioned at the top of each shaft to keep the pins in place. Once you insert a key, the pins are pushed to varying heights. The wrong key keeps pins inside the plug and housing. The cylinder will not rotate if this is the case.

Once you insert the correct key, the pins will fall into place along the notches and grooves of the key. None of the pins will still be inside the plug or housing, so the cylinder will be able to move. You would then turn the key to slide the deadbolt out of the frame to allow the door to be opened.