Types of Door Locks

When looking for new or replacement locks, the wide range of different types of locks can be overwhelming! With different types of locks for doors and windows it can be very difficult for anyone with no lock knowledge to recognise and then find a new lock. This guide takes you through the different types and styles of locks including when and where to fit to fit them. Lets start with door locks, there are a couple of door lock types, each of which can then be further broken down into different types and security levels.

Mortice Locks

Mortice locks are easy to identify as they are fitted into a door rather than onto the surface of a door.

Mortice locks are available in two distinct versions, Sash Lock and Dead Lock. The two are easy to tell apart, both have the locking dead bolt that is used to lock and secure the door, the dead bolt is locked and unlocked by a key. Sash locks have an additional latch bolt that is operated by a pair of lever handles, this added latch bolt is used to hold the door in the closed position. In the example above you can see the sash lock has a pair of handles on the outside of the door and a key hole, where as the dead lock has just a key hole. Mortice locks can be fitted to wooden or metal doors and come in various security levels, from 2/3 lever locks that are used on internal domestic doors, 5 lever locks that are more commonly found on internal office doors, right up to 5 Lever British Standard locks that are used on external doors and often required for insurance purposes.

• Lock is fitted inside the door
• Dead or sash lock variants
• Different levels of security

Measurements for mortice locks can be critical - Click here for dead lock measurements and here for sash lock sizes

Rim Locks

Locks that are mounted to the surface of a door are know as rim locks. Rim locks can be divided into two main categories, night-latch rim locks and more traditional rim locks with a long skeleton style key.

Nightlatch locks can be identified by their external rim cylinder, which is operated by a small cylinder key and internal lock case with small handle to open the door. A single large latch bolt is used to hold the door closed and provide locking force. Nightlatch locks are available in varying security levels to suit locking requirements, from simple night latches that will just hold the door closed, to deadlocking latches that can't be forced open and full British Standard Night Latch locks that are insurance rated. Traditional rim locks, as the name suggests have an old look and feel to them and are often found on older style homes. These type of rim lock offer low security levels, which make them ideal for internal, bedroom and bathroom doors.

For a guide to rim lock measurements click here

Locks for UPVC Doors

Over the last 20 years, plastic UPVC doors have become very popular due to their low maintenance and relativity low prices. As these doors and not very thick, standard mortice or rim locks are not suitable. To make these door secure a new type of locking mechanism has been developed which operates in a very similar way to patio door locks.Multi point locks as the name suggest use a number of locking points to secure the door, typically a latch bolt and deadbolt are found near the key hole, other locking rollers or hooks are then located above and below the handles, these give the door great locking strength in the case of an attempted force entry.Multi point locks are operated by a cylinder lock that is passed through the door and lock case so the cylinder can be operated from either side. These cylinder locks can have a key on both sides or a key on the outside and a thumb-turn on the inside to operate the lock. To full operate multi point locks, a lift of the handle is sometimes required, this engages all the locking points, the cylinder lock is then used to lock the bolts, rollers and hocks in place.