What Is a Euro Profile Cylinder? A Complete UK Buying Guide

If you've ever looked closely at the lock on a UPVC, composite or timber door, there's a good chance you were looking at a euro profile cylinder. It's the small, keyhole-shaped fitting that sits inside a multipoint locking mechanism, and it's by far the most widely used lock cylinder on modern UK doors.

Supplied by Trade Door Handles, trusted UK supplier of architectural ironmongery since 1976, with quick nationwide delivery.

A euro profile cylinder (sometimes just called a euro cylinder or euro lock) is a cylindrical lock barrel with a distinctive "figure of eight" cross-section. It's designed to fit a standardised euro profile lock case, which is why cylinders from different manufacturers are largely interchangeable, provided the size is right. Because of that standardisation, a euro cylinder lock is one of the easiest components to upgrade on an existing door without replacing the whole lock case or the handles.

They're used across a huge range of properties and trades, including:

• Homeowners replacing a worn or damaged lock barrel

• Landlords and property managers upgrading security between tenancies

• Joiners and builders fitting new external doors

• Locksmiths responding to break-ins or lock-outs

• Facilities teams managing schools, hospitals and commercial premises

There are two main operating styles:

• Key-operated euro cylinders need a key on both sides of the door.

• Thumbturn euro cylinders have a key on the outside and a rotating knob on the inside, so the door can be locked or unlocked from indoors without a key. This is popular for fire escape routes and back doors, where you need to get out quickly in an emergency, but it can reduce security if fitted to a door with glazing near the lock.

Euro cylinders aren't all the same shape:

• A double euro cylinder has a key both sides and is the standard fitting for most front and back doors.

• A single euro cylinder has a key on one side and a fixed knob or plate on the other, often used for garage doors, sheds or internal doors.

• A half euro cylinder is a short cylinder used with a nightlatch, rather than a full multipoint lock case.

1. Remove the existing cylinder by undoing the single fixing screw on the door edge (with the door open) and gently pulling it out.

2. Measure from the centre of the fixing screw hole to the end of the cylinder on the outside face of the door.

3. Measure from the centre of the fixing screw hole to the end of the cylinder on the inside face of the door.

4. Add both measurements together to check against the overall length if needed, but always order using the two individual figures rather than the total.

Getting this wrong is one of the most common mistakes when buying online, so it's worth double-checking before you order, especially if you're working from an old or worn cylinder where the fixing screw hole may not be perfectly central.

The TS007 kitemark scheme rates cylinders from one to three stars based on their resistance to snapping, picking, drilling and bumping:

• A 3-star cylinder meets the highest standard on its own and is the recommended minimum for most external doors today.

• A 1-star cylinder combined with 2-star security door furniture also meets the TS007 standard, since the two components work together.

• Many insurers now expect a TS007 3-star, or 1-star-plus-2-star combination, as standard on external doors, so it's worth checking your policy wording.

When selecting a replacement or upgrade, it's worth thinking through:

• Door type – UPVC, composite and timber doors all use the same standard cylinder sizing, but always confirm compatibility with your existing lock case.

• Security rating – Look for TS007 3-star or anti-snap certification on any external door.

• Key or thumbturn – Consider fire escape requirements versus the added security of key-only operation.

• Keyed alike options – A keyed alike euro cylinder lets you operate front, back and garden doors with the same key, which is popular for landlords managing multiple properties.

It's also worth thinking about the finishing touches around the cylinder itself. Euro profile escutcheons cover the keyhole neatly and protect the surrounding door finish, while many customers choose door handles on backplates with a matching euro profile cutout to combine the handle and cylinder cover in a single, tidy fitting.

Our team has been supplying trade and retail customers with locks and latches for decades, and we're always happy to help confirm sizing or security ratings before you order.