Types of Door Knob Locks

Door knob locks are an important part of any home security system. Most types of door knob locks use a cylinder that locks into place when the key is turned. When the cylinder is locked, the door latch is forced into the slot in the strike plate and the door is immobilized.

Latch Lock

The latch lock is the most common type of door knob lock. The lock cylinder is contained in the door knob itself and uses an angled latch to secure the door in the strike plate. Latch door knob locks can be unlocked from the inside and may also have a keyhole on the outside.

Single Cylinder Deadbolt

A single cylinder deadbolt is installed separately from the door knob latch lock. Instead of an angled latch, deadbolts use a locking bolt that is flat on both sides. This makes it more difficult for a thief to open the lock by sliding a credit card through the door jamb. A knob on the inside of the door opens and closes the deadbolt.

Double Cylinder Deadbolt

Double cylinder deadbolts are the most secure type of door knob lock. A key must be inserted into a keyhole on the inside of the door in order to turn the cylinder. This prevents a thief from being able to open the door by breaking a nearby window and unlocking the deadbolt.

Surface-Mount Deadbolt

A surface-mount deadbolt uses metal plates with interlocking teeth to secure the door. One plate is mounted on the door and another one on the wall. When the deadbolt is locked, a bolt runs through the teeth to hold the two sides together.

Keyless Lock

Keyless door knob locks use an electronic keypad to control the latch. When the correct security code is entered, the latch releases and the door can be opened.