Door Lock Buying Guide | Door Lock Types Explained | Toolstation

Door Lock Buying Guide

Door Lock Buying Guide

Door locks are the first line of defence for buildings, but buying the wrong type could put you at risk of burglaries.

Using a British Standard approved lock for your home may be required by insurance companies and, if not, could still save you a lot of money insuring your property.

There are a number of locks to choose from – some used on their own, some to supplement other defences – including mortice locks, euro locks and surface locks.

Choosing a lock? Consider the level of security you need, the material of the door, insurance policies and budgets to find the right one for your needs.

Types Of Mortice Door Lock

Mortice locks fit into a pocket in the edge of the door – called a mortice – and have a locking bolt which moves back and forth into the door frame.

Mortice locks range from 2 to 7 levers, with higher security with every lever added. Here at Toolstation, you’ll find 3 lever and 5 lever varieties. 5 lever locks are commonly used on external doors, sometimes alongside nightlatches to add extra security.

The two main types of mortice lock are sash locks and deadlocks.

Viscount 5 Lever Mortice Deadlock
3 Lever Mortice Deadlock
ERA 3 Lever Mortice Sashlock

Types Of Euro Cylinder

Euro cases look similar to sash locks and deadlocks, but are mainly used for PVCu doors instead of timber doors. They have space for an inexpensive, replaceable euro cylinder lock – ideal for landlords who need to change the locks when a new tenant moves in.

Cylinders come as single, double and thumbturn varieties. Single cylinders only lock from one side, double cylinders lock from both sides, and thumb turn cylinders unlock by rotating a solid metal thumb turn instead of a key.

Different standards of cylinder are available, including standard 6-pin, 1 star kitemarked, and 3 star kitemarked – the latter being the only security recommended for external doors, unless 1 star cylinders are used with 2 star door hardware.

Euro Cylinder Sash Case
Euro Cylinder Dead Case

Other Door Lock Types

Rim Locks
Digital Push Button Lock

Door Lock Finishes and Materials

Satin Finish Door Locks

Satin finish locks have a slightly matte look, giving them a sleek and modern appearance. They’re also better at hiding fingerprints because of the slight milky appearance.

Polished Finish Door Locks

Locks with a polished finish are slightly glossier, for a traditional, more luxurious look. They’re highly corrosion resistant too – great for withstanding the elements!

Brass Door Locks

Brass locks are made of a metallic alloy of copper and zinc. It’s a strong material that doesn’t rust – meaning it’s ideal for locks where moisture could be a problem.

Chrome Door Locks

Chrome locks are coated in the chemical element Chromium and are a steely grey colour. They’re a popular choice to give a modern appearance and increase the durability of locks.

Electro Brass Door Locks

Electro brass is a popular coating, made by using an electrical current to apply a thin layer of brass to the surface to the lock. It’s a cost effective and stronger alternative to solid brass.

Nickel Brass Door Locks

Nickel has a slightly glossy, yellow hue compared to chrome coated locks and offers corrosion resistance, as well as adding brightness and lustre to the surface.

Door Lock Accessories


Pulls are added by the lock to the door, and allow you to pull the door open when a handle isn’t needed – such as deadlocks and euro dead cases.


Escutcheons are flat pieces of metal to protect the keyhole and add style to a door. There are also thumbturn escutcheons which function with the lock to turn it and slide the bolt.

Bathroom Indicator Bolts

Bathroom indicator bolts have signs on the bolt to indicate whether the bathroom is engaged or vacant, making them ideal for offices, schools and within the hospitality industry.


Door handles are necessary for some locks to operate a latch, or you can use them as a door pull. You’ll find these in a number of styles to suit your taste and decor.

Door Viewers

Door viewers – commonly used for apartment front doors – are installed into a drilled hole in the door and can add extra security by allowing you to see who’s knocking before opening the door.

Door Chains, Bolts and Hooks

Door chains, bolts and hooks can be used to add extra protection to a door in addition to a lock. Bolts and hooks are also ideal, inexpensive and easy-to-install bathroom locks. Door chains allow the door to be slightly opened for extra security.

Frequently Asked Questions

  • What is the most secure form of door lock?

    The most secure type of lock depends on the type of door. For uPVC doors, opt for a euro sash case or euro dead case alongside a 3 star kitemark cylinder. For timber doors, use a British Standard BS3621 approved 5-lever mortice model such as a sashlock or deadlock.

  • What type of locks should be used on exterior doors?

    The only locks that should be used on exterior doors are , push button locks, or 3 star kitemarked euro sash cases and dead cases.

    For added security, you can use surface locks – but these should never be relied on alone.

  • What is a deadbolt lock?

    A deadbolt lock is a type of deadlock with a bolt that extends into the door frame or floor, automatically locking when the door is closed.

  • Why do front doors have two locks?

    Front doors sometimes have two locks for extra security. Sometimes one lock is for security, and the other is for style – particularly if you’re looking for a traditional Victorian aesthetic.

  • What is a normal door lock called?

    A normal door lock is likely to be a mortice lock – either a deadlock, sashlock, euro sash case or euro deadcase style. These offer high security for external doors and also act as a visible deterrent because burglars know they’re difficult to overcome.

  • What is a spring latch lock?

    A latch is a commonly used spring-loaded bolt with a locking mechanism located inside the door which retracts when a door handle or doorknob is operated.

  • How can I make my front door more secure?

    To make your front door more secure, it’s important to get a lock that meets the required standards – a 5-lever mortice lock with BS3621 British Standard approval, or 3 star kitemarked in the case of a euro lock and cylinder.

    You can also add an extra surface lock or door chain, as well as a spy viewer so you can see who’s knocking before opening the door.

  • How do you stop a door from being kicked in?

    If you want to stop a door from being kicked in it’s important to choose a British Standard BS3621 approved or 3 star kitemarked mortice lock – such as a sashlock or deadlock.

    These types of lock are anti-pick, anti-bump, anti-drill and anti-snap.

  • What is the star rating on locks?

    Euro cylinders are given ratings – from standard to 3 star – which tell you how secure the lock is. Standard cylinders offer medium levels of security and can be relied on for internal doors.

    Cylinders with a 1 star kitemark are anti-pick, anti-bump and anti-drill, making them a high security option for external doors. By combining a 1 star cylinder with 2 star door hardware such as handles, the lock is upgraded to a 3 star cylinder.

    Cylinders with a 3 star kitemark offer the maximum level of security and are anti-snap alongside all the benefits of 1 star cylinders.

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