Dead Bolt Basics

A dead bolt is a locking mechanism that provides more security than standard key-operated locks, since the heaviness of the locking bolt increases the amount of time it would take for someone to break through the door. Typically, a dead bolt is installed as a supplement to a handle lockset, to achieve greater home protection. Dead bolt locks can also be purchased for interior doors where extra security is desired.

Deadbolts can only be released by manually rotating the lock's cylinder, because there is not a spring mechanism. Cylinder-based locks use a pin tumbler apparatus that locks inside the cylinder. Basically, your door key turns a cylinder, which turns an attached cam, thus retracting or engaging the bolt.

Since they are mortised into the door, deadbolts are commonly used in newly purchased doors or as upgrades to existing door hardware. Almost all door types, from large entry doors to smaller residential doors, can be secured with dead bolt locks.

When selecting a dead bolt, keep these hints in mind:

• Choose a stainless steel bolt that is a minimum of one-inch long. Since the dead bolt secures your door into its frame, a longer bolt will increase the force needed to pry through the door.

• Look for hacksaw resistant features like a bolt with a rotating steel pin or roller insert.

• Look for pry or wrench resistant features like a free-spinning cover on the outer cylinder.