Bored cylindrical door locks

Cylindrical door locks, also known as bored locks, are the most common type of lock mechanism used in residential and commercial properties. They are the simplest to install and replace and the most affordable.

They are named for their cylindrical shape and the way they are installed by boring two holes into the door: a large hole in the face of the door for the lock body, and a smaller hole in the door edge for the latch bolt. 

The lockset of a cylindrical door lock typically includes a keyhole and a knob or lever that can be turned to open the door. Lever door locks cost more money than knob types as they are more expensive to manufacture, but levers are also much easier to operate and should be chosen for doors that are opened and closed by elderly people and children. 

The lock can be disengaged using the correct key on the outside or by turning a small knob or button on the inside. This type of lock offers a basic level of security and is often used in combination with a deadbolt for additional protection when it is used for the main door of a property.