Guide To Common Locks Found on External Doors

There may come a time when you will want to know what type of locks are fitted to the front and back doors of your property. This may be because your home insurance company asks for this information when you apply for a quote.  Or maybe there have been break-ins in your area and you want to check if the locks protecting your property are up to the job. In this simple guide, we will identify the most common types of locks and their uses.

1. Five Lever Mortice Deadlock

A 5 lever mortice deadlock is a type of lock that is installed into the door material (morticed). The door is locked and unlocked from the inside and outside using a key. Although 3 lever mortice locks are available, 5 levers are much more secure.

This type of lock is most commonly found on wooden external doors. For optimum security, the lock should be kitemarked and conform to BS3621. Often insurance companies require this standard where these locks are fitted. The kitemark, number of levers and BS3621 should be visible on the faceplate of the lock.

An additional benefit of this type of lock is the ability to be “keyed alike”, which means, a single key can be used for multiple exit/entry doors where this type of lock is fitted.

2. Cylinder Lock

Euro cylinder locks are one of the most common locks found on external doors. This is because they are often found on UPVC and composite doors along with multipoint locking systems.  This type of lock incorporates a series of different length pins, which follow the exact pattern of the key. When the key is inserted and turned, the pins are moved to the correct position. This allows the door to be locked or unlocked. This type of lock can also be “keyed alike”.

4 types of euro cylinder lock

• Double euro cylinder lock – can be locked/unlocked with a key from both sides
• Single euro cylinder lock – can only be locked /unlocked with a key from the outside only e.g. garage lock
• Full thumb turn euro cylinder lock – can be locked/unlocked with a key from the outside and has a thumb turn option on the inside. This type of lock is often used in the main hallway access to multiple dwellings
• Half thumb turn euro cylinder lock – thumb turn locking/unlocking from one side only e.g. inside bathroom

In the past, there have been major problems with the euro cylinder lock. A weakness in the original design enabled burglars with the right tool to snap the cylinder of this type of lock in just a few seconds. This is commonly known as lock snapping. As a locksmith in Orpington, I have seen this technique used many times by intruders to gain entry to a property. Fortunately, high security, anti-snap euro cylinder locks are now available. This newer type of cylinder lock has been manufactured with features which prevent the cylinder from snapping. I would highly recommend that any external doors still fitted with standard euro cylinder locks are upgraded to anti-snap as soon as possible.

3. Multipoint Locking System

As with cylinder locks, multipoint locking systems are most commonly found on UPVC and composite doors e.g. front door, back door, patio doors etc. When locked, the bolts in the door are secured in the frame at multiple points. There should be a minimum of 3 locking points which are usually located at the top, bottom and the middle. The movement of the bolts is controlled by a single cylinder lock (you usually also have to lift the handle to lock). This type of lock is very secure but as mentioned above, it must be fitted alongside an anti-snap euro cylinder.

4. High Security Nightlatch

This type of lock is relatively easy to spot as it is most commonly found surface mounted to the inside of wooden doors. They are locked /unlocked on the inside by turning the knob/lever and on the outside by inserting a key. These locks are often called “Yale Locks” – a nod to the original inventor and manufacturer of this type of lock.

The main downside of this type of lock is that it usually requires an additional lock for added security. For this reason, you will usually find a mortice deadlock fitted alongside.

There are three main types of nightlatch, with differing levels of security.

• Standard Nightlatch (Non Deadlocking)

This type of lock has a rim cylinder on the outside which needs a key to open. On the inside, there is a knob/lever with a “snib”.

The night latch can only be set or “snibbed” (in the open or closed position) via the snib button. In the open position, it can be used to stop the door from locking behind you. The snibbed (closed) position can be set when you are in for the evening/night.

This type of lock is commonly used where there are multiple occupants in a single dwelling because it prevents anyone from being accidentally locked in. However, when the lock is not in the “snibbed” position, it can be subject to “credit card slipping.”

• Deadlocking Nightlatch

This lock is very similar to the standard nightlatch but with the added security of being able to deadlock the property from outside with a key. It offers better security against credit card lock slipping. Some deadlocking nightlatches also have a key lockable internal handle.

• Auto Deadlocking Nightlatch

This is similar to the Deadlocking Nightlatch but with automatic deadlocking when the door is closed. This is achieved via an additional pin above or below the bolt which is depressed into the casing any time the door is closed. Most also allow inside deadlocking of the handle via a key.

There are of course many other types of locks available including the latest smart locks which are becoming very popular. Smart locks don’t require keys at all and can be operated by your mobile phone, fob or card. However, whichever type of lock is fitted, the main thing is that it is secure enough to keep intruders from breaking into your home.

If you are still unsure if your locks are up to scratch, or if you want to upgrade them, get in touch with a local locksmith. They will be able to offer good advice and options to suit all budgets.

KLS Locks is an affordable, experienced 24-hour locksmith. We are based in Orpington but cover the whole of Kent and South London. We offer a range of locksmith services including Lock Replacement and Repairs, uPVC Door and Window Repairs, Smart Home Security Solutions as well as services for commercial businesses. Get in touch to find out more or give us a call on 07830 832759