Door Lock Types

Main Parts of a Door Lock

To understand the difference between the different types of locks, it is good to know first the different parts of a lock. A door lock generally has three main parts: the cylinder, the bolt, and the strike plate.

Cylinder

The cylinder is the part of the lock where you insert the key. It is essentially the section that brings the “locking mechanism” to your locking system. Inside the cylinder are several pins that move when the key is inserted. All of the pins inside the cylinder will move only if the key fits the cylinder correctly. The lock will then unlock once the key reaches the last pin, allowing you to move the bolt and open your door. The lock will remain locked if the key does not fit the cylinder correctly.

There are two categories of the cylinder lock. One is the single-cylinder which only has space for a key on one side. The key side is on the external part of the door, while the other side is a knob or a handle that you can lock from the inside of the door. The other one is the double cylinder. Double cylinders do not have a single knob. To lock and open doors using double cylinder locks, you need a key on either side of the door. You can usually find double cylinders in places where you don’t want anyone to be able to lock the door from the inside without a key.

Bolt

Bolts are the part of the door lock that you can move once the key fits within the cylinder. It is the part that moves in and out of the carved-out part of the door frame. There are two common types of bolts: the deadbolt and the spring bolt. 

A deadbolt is a locking mechanism that cannot be moved without the correct key. This means that, for a deadbolt, you need to have a key to open the lock before you can move the bolt. On the other hand, spring bolts have a spring within that allows the bolt to retract once it touches the door frame or the lip of the strike plate. The bolts will then automatically extend back to the carved-out part once the door fully closes.

Deadbolt provides more security than the spring bolt, but a deadbolt requires you to always have a key with you. Spring bolts are better than a deadbolt for people who forget their keys most of the time. Spring bolt is ideal for doors that need to be closed but do not need to be locked all of the time.

Strike Plate

The strike plate is the piece of metal attached to the door frame. It holds the door closed once the bolt fully extends to the hole of the strike plate. Strike plates usually come with two holes where it can be screwed to the door frame, making it easy to attach as well as replace when it gets damaged.

Different Types of Door Lock

Choosing the right type of door lock is essential for your security as well as convenience. Additionally, when applying for home insurance or looking for home insurance deals, you will also usually be asked what type of locks you have fitted on your outside doors and windows. 

If you have the home insurance industry approved locks fitted on your doors, you could get a discount and may even save a lot of cash on your home insurance premiums. Otherwise, you may find yourself paying a higher premium for your home insurance. Thus, we listed here a guide about the best and most common types of locks that conform to the standard, especially those types of door locks home that can be found in home insurance policies.

1. Mortice Locks
2. Multi-point Locks
3. Rim Automatic Deadlatch/ Night Latch

Mortice Locks

A Mortice Lock is one of the most common door lock types you can see in home insurance policies. Mortice Locks include heavy-duty latches that make it popular for their strength and level of security. Consequently, this type of lock mechanism is commonly used not just in homes but also in residential properties in the UK. A mortice lock requires a mortice to be cut into the edge of the door. This mortice or pocket is where the mortice latch will be fitted to.

A popular mortice lock is the 5 Lever Mortice Deadlock which is commonly fitted to wooden doors. It provides a good level of security as it is locked from both the inside and outside with a key. Thus, this type of lock is most commonly used in external doors, particularly the front door and the back door. Mortice deadlocks are not found on doors like the uPVC (Unplasticized Polyvinyl Chloride) & composite doors.

Aside from the 5 Lever Mortice Deadlock, there is also the 3 Lever Mortice Lock. However, this type of lock is less secure since it has fewer levers. Fewer levers mean that there is a high risk of key duplication. Thus,  a 3 Lever Mortice Lock is not approved by the British standard. To be insurance and standard approved, it is best to use the 5 Lever Mortice Deadlock and ensure that it conforms to the current approved British standard.

To identify whether your mortice lock conforms to the standard, the quickest and right way is to look at the faceplate and see if these are engraved: British Standard Kitemark, Number of Lever, and Standard Number. A mortice lock that conforms to the standard is more secure because of its use of hard plates for protection against drilling. If the mortice lock is not standard-approved, the lock is usually fitted with a Nightlatch for added security.

Multi-Point Locks

A multi-point lock is a key operated locking system that is fitted into the body of the door.  It has multiple bolts that will engage to the door frame when the door locks. This locking system is commonly operated with a euro cylinder lock. This lock system is approved as it offers a high level of home security due to the lock bolting the door into the frame. It often has three locking points (sometimes 4 or 5) that simultaneously lock when you turn the key.

You can often find this locking system on uPVC and composite doors, especially on entrance doors. It can also be fitted to other doors like timber and aluminium doors. The multi-point lock is often found on the external front door and external back door. Despite its several locking points, only a single cylinder is required for a multi-point lock. 

However, you must know how the lock is operated the right way to fully lock the door properly. There is a risk that your key may get broken and stuck inside the lock of your uPVC door, so make sure to use it correctly.

Night Latch or Rim Automatic Deadlatch

Another generally approved lock for insurance is the rim automatic deadlatch or night latch. However, this type of lock is not recommended to be the only lock fitted on your door. For extra measure and to double the security, most providers would prefer the rim automatic latch to be mounted with either the mortice lock or the multi-point lock.  Night latch is less secure because it is only mounted on the surface of the front door.

The main difference between a rim lock and a mortice lock is that rim locks are mounted on the surface of the door while mortice locks are mounted within the door edge. Thus, the disadvantage of using rim locks is that it cannot be used and operated alone. Still, rim locks or night latches can be useful in improving security. Night latches can also be easily used as they lock automatically once shutting.