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Door Locking Systems

Explaining the variety of Locking Systems used throughout the house
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There are many types of Locking Systems that suit different needs, to list every type would be exhaustive. However, the following provide an overview of all the main types of Door Locking Systems.

Please note that a bad lock installed correctly is better than a good lock installed badly. Security is only as good as the weakest point. Our experienced team are always here to help, so please call if you have any questions.



The defining characteristic of the Deadlock is that the bolt of the deadlock has to be moved manually via a key or thumbturn. This method of locking/unlocking greatly reduces the risk of the bolt being prised open (jemmying the lock).

Deadlocks come in several varieties, most commonly: Mortice Locks and Rim Locks.

Sash Locks

Sash Locks

Sash Locks are often confused with Deadlocks.

The main difference is that Sash Locks have a Deadbolt and a latch. The latch is sprung and typically operated by a handle whilst the deadlock is not sprung and operated by a key or thumbturn. Having both a latch and a deadbolt means that when just the latch is used anyone can come and go through the door just by operating the handle. When the door needs to be more secure the deadlock is also used ensuring that only users with the correct key can withdraw the deadlock and open the door.

Sash Locks normally comes in two different sizes, this being A) 2.5” back set (measured from the leading edge of the door to the keyhole) and B) 3” back set. There are other uncommon sizes, such as 2” / 6”, however the normal variants are 2.5” and 3”.

There are two normal ways of locking a Sash Lock. The standard English way is via a Mortice Key and new variants are via Euro Cylinder / Oval Cylinder. Both variants have their own benefits.

Please see the Deadlock section for more information on how it works.

Rim Lock

Rim Lock

A Rim Lock is a lock that is installed to the surface of the door leaf.

Normally this type of lock would be used internally as they are marked as low security locks. For external use, a Night Latch would be used.

Rim Locks are normally installed on thin doors which will not take a Mortice Lock. Given that the lock is attached to the Door Face, it makes it easier to pry off Door and therefore makes it less secure than other methods. They are however slightly easier to install.

Given that the Rim Lock sits on the Door Face, it does mean that the door must have sufficient space to house the lock. If there is glass, or the likes of, then you will require a thinner / narrow lock.

Rim Locks come in different variants including but not limited to: Sash Lock, Deadlock and Night Latch.

Nightlatch / Night Latch

Nightlatch / Night Latch

Night Latches are sometimes referred to as Yale locks. Yale is just a brand, similar to the association of Hoover’s with vacuum cleaners. The technical term however is Night Latch.

They are a type of  Rim Lock as they are attached to the Door Leaf itself. However, they are normally installed onto an external door given that they have a higher security rating. They come in two sizes, this being 40mm and 60mm.

Automatic Deadlocking Night Latch

Automatic Deadlocks have a Pin above or below the Latch. When the door is closed, this Pin then activates the Deadlock. This reduces the chances of the lock being opened without a key.

This type of Night Latch often has Deadlocking via Key as well.

Night Latch Security Rating (with British Standard Kite mark)

We would never recommend using just a Night Latch on its own. It is always best practice to have a Night Latch in addition to a BS (British Standard) Five Lever Dead Lock. For optimum security, we always recommend installing the Night Latch at shoulder height, and deadlock to be installed at knee height. This greatly increases the security of the door itself.

As well as placement, we always recommend buying products with the BS Kite Mark (British Standard). These have been tested rigorously and greatly reduces the chances of unwanted visitors.

Yale Lock

Yale Lock

As mentioned before in the Night Latch section, the Yale lock is actually a brand of lock rather than a type of lock. Generally speaking, people are looking for a Night Latch rather than a Yale. It is similar to the association of a Hoover and a vacuum cleaner. The brand brought out products early on and the name simply stuck.

At Poyntell we always offer a broad selection of locks and always recommend looking at a wider range of brands.

For more information on this type of lock please see the Night Latch section.

Mortice Lock / Mortise Lock

Mortice Lock / Mortise Lock

When a lock sits within the body of the door rather than on the surface it is referred to as a mortice lock. The Box Keep or Strike plate is then installed into the Door Frame to receive the bolt and / or latch.

This method of locking is very secure as the components are embedded into the door itself.

Various types of locking mechanism can be morticed into a door to achieve the desired function and security level applicable to your need.

5 Lever Mortice Lock / Lever Tumbler Lock

Lever Locks

A Lever Lock refers to a type of lock that contains small levers that, in simple terms, are set at different heights and will only align correctly when the right key is inserted into the lock. The number of levers within a lockcase can vary from typically 3 to 5 levers. With the correct key inserted the levers will align and allow the key to turn to either ‘throw’ or retract the locking mechanism.

It is often considered that 5 Levers provide the optimum security for a lever lock on a standard domestic front door, hence why the term ‘5 lever lock’ has become quite commonly used.

The fact that different locks have the same number of levers does not mean that the locks offer the equivalent security level. We stock a number of different types of locks with various functions and security levels, it is important to be aware of this as some products will meet your insurance requirements and some will not. We can advise on all aspects and considerations for choosing the right lever lock for your particular need.

Multi-point Lock

Multi-point Lock

Multi-point locks are normally found on uPVC doors, however they can be found on wooden / metal doors too. As the name suggest, the activation of the lock normally initiates multiple locking mechanisms. The mechanisms are normally executed from the top, middle and bottom of the door. In addition to the locking points, a Multi-point lock normally incorporates a latch.

These are normally the lock of choice on uPVC / Composite doors as they lack the rigidity of a wooden door. Therefore, the locks not only keep the door shut but prevent the door from being forced open.

uPVC Locks

uPVC Locks

During the 80’s and 90’s there were hundreds of double glazing companies that created many different types of doors and locks. However, generally speaking when someone refers to locks for uPVC, they generally mean the Multi-Point Locking systems.

Type, brand and size can differ greatly, so it’s always best to check with a professional before purchasing anything.

We have a highly specialised team who know a great deal about different lock types. Call us on 01580 892 902 or email us on info@poyntell.com if you have any queries about your lock type.

Poyntell Master Key System

Poyntell Master Key System

The Poyntell One Key System does exactly what it says on the tin.

It allows you to have a unique key or system of keys to give you access to all locks, some locks or just one lock on your site. You decide whether you want your key to open all locks whilst other key holders are restricted to being able to open a selection of locks or just one lock. From the main entrance to the office doors, from the warehouse to outbuildings all locks can be on one secure, configurable key system that is unique to you. Your system can also be extended to control key access to machinery or powered equipment.

For more information, visit our Poyntell Master Key System web page.

Key Cylinders

Key Cylinders

Key cylinders are used in conjunction with lockcases that are specifically designed to accept them and removes the need for the lockcase to have any levers. Key cylinders come in various shapes and lengths and all basically work on the principle that a when a correctly configured key is inserted they allow a cam or cam bar to be rotated which, when the key cylinder is installed as part of a key cylinder compatible lockcase, will operate the lockcases bolt or latch. Unlike lever locks which have the key inserted directly into the lockcase key cylinders control the operation of the key. As the key cylinder is a separate self contained entity to the lockcase it allows for a wide variety of security measures to be included in its design to improve the security level of the lock package. Due to the design of key cylinders their internal components allow for all sorts of key configurability such as master keying or keying alike enabling a wide range of keying options to be offered.

Key cylinders have become more and more popular with the Euro key Cylinder being the product of choice generally across Europe whilst other shapes have gained traction in Scandanavia (Swedish Oval key cylinder) and the Rim Cylinder and UK Oval cylinder in the UK. The majority of upvc (patio or front doors) in the UK now feature a locking mechanism that incorporates a euro key cylinder but they can also be used in doors of all types of construction such as timber or metal doors as padlocks. The same key can operate in different shapes of key cylinders to give ultimate flexibility of use and convenience I.E the key for your main door can also be used in a padlock on a remote building and on a switch lock that controls powered items.

A correctly specified and fitted key cylinder provides a high level of security and user convenience but specified and fitted incorrectly they can be vulnerable to attack. We can advise on the different types, uses and security of key cylinders to arrive at the right solution for your needs.

British Standard / BS Locks

British Standard / BS Locks

A lock becomes a British Standard Lock once it meets the security requirements and is tested to those standards by an independent body, only then will the product be able to display the BSI (British Standards Institute) kitemark symbol. There is an important distinction between products that conform to a British Standard (BS) and those that are certified to a British Standard. If a product states that it conforms to a BS then it has usually been produced along the lines of the relevant BS standard but has not been tested to the standard. If a product is certified to the BS then it has been manufactured, tested and passed the BS criteria and can display the relevant kite mark to show that the product has been certified in its performance to that BS. This is an important distinction that can catch clients out and invalidate your insurance, it is always best to take advice on the best products to use to meet your individual requirements.

Often insurance companies will require certified BS locks to be placed on all external doors in order to cover the property. It is also important to remember though that any lock must be fitted and operated in the correct way for it to work reliably and not invalidate the accreditation afforded to the lock.

You can always tell if a lock is BS certified by the kitemark as seen in the image adjacent.

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