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Lock Installation GuideEuro Cylinder Locks: What They Are, How They Work, and Which One Is Right for Your Door
Written by Our Locksmith · Professional Locksmiths · South London · 7 min read
What Exactly Is a Euro Cylinder Lock — and Why Is It on Nearly Every Door in the UK?
A euro cylinder lock is the small, cylindrical mechanism that sits inside the lock housing on most modern uPVC, composite, and aluminium doors. When you push your key into the barrel and turn it, you're operating a euro cylinder. It's the most widely used lock type in the UK — and unfortunately, one of the most targeted by burglars when the wrong spec is installed.
The euro cylinder controls whether your door locks, deadlocks, and whether the thumb-turn (the inside lever) functions correctly. Get the wrong size, the wrong security rating, or the wrong brand — and your door becomes a soft target. That's why at Locksmith South London, our most common job isn't lockouts — it's replacing weak cylinders before a break-in happens.
In this guide, we cover everything: how to upgrade your locks, how to measure your cylinder, what the star ratings mean, and which brands our engineers trust. We also work with anti-snap locks — a separate but closely related subject that every South London homeowner should understand.
A high-security Avocet ABS euro cylinder — rated 3-star TS007 and Sold Secure Diamond
How a Euro Cylinder Lock Actually Works
Inside every euro cylinder are a series of spring-loaded pin stacks. When the correct key is inserted, it pushes each pin to the exact height needed to align the "shear line" — the gap between the inner plug and outer housing. Once all pins align, the plug rotates and retracts or extends the lock bolt.
The cylinder has two ends: the external side (where you insert your key) and the internal side (where the thumb-turn sits). Both are connected to the central cam, which drives the door's locking mechanism. Higher-security cylinders add additional layers — anti-pick pins, anti-drill hardened steel inserts, and anti-bump mechanisms — to defeat every known attack method.
The weak point in standard cylinders is the snap point. When too much of the cylinder protrudes from the door face, a burglar can use a screwdriver and brute force to break off the end, exposing the cam and opening the lock in under 10 seconds. That's why cylinder size matters as much as security rating.
How to Measure a Euro Cylinder — Getting the Size Right
Euro cylinders are measured in millimetres from the centre of the fixing screw hole to each end. A cylinder described as 35/45 is 35mm on the external side and 45mm on the internal side — 80mm total. This is written as external × internal.
How to measure your current cylinder:
- Remove the door handle (undo the two screws on the rose/plate)
- Locate the small grub screw on the edge of the door — undo it
- Turn the key slightly and slide the cylinder out
- Measure from the centre of the screw hole to each end
- Note the format: [external]×[internal] (e.g. 40/40 or 35/50)
The most common mistake is buying a cylinder that's too long on the external side. If more than 3mm protrudes from the door face, it becomes snapable. Our engineers always fit cylinders flush to the door and use anti-snap specific sizes where needed.
Understanding Euro Cylinder Star Ratings: What TS007 and Sold Secure Actually Mean
The TS007 standard (published by the British Standards Institution) rates euro cylinders on a 1–3 star scale based on resistance to: snapping, drilling, picking, bumping, and extraction. A 3-star TS007 cylinder is the highest independent certification available in the UK.
⭐ 1-Star TS007
Basic anti-snap protection. Minimum acceptable for most home insurers. Better than nothing — but not our recommendation.
⭐⭐ 2-Star TS007
Anti-snap plus anti-pick. Good security for most residential properties. Accepted by most UK insurers.
⭐⭐⭐ 3-Star TS007 ✓ RECOMMENDED
Maximum protection: anti-snap, anti-pick, anti-drill, anti-bump, anti-extraction. What we fit on every job.
Sold Secure (SS312 Diamond) is a parallel certification scheme that also tests to the highest level. Cylinders like the Ultion and Avocet ABS hold both TS007 3-star and SS312 Diamond — they are effectively the gold standard for residential security in London.
The Most Secure Euro Cylinders We Fit in South London
These are the brands our engineers carry and fit daily. All hold TS007 3-star certification and Sold Secure Diamond status. We stock them in all common sizes.
Ultion by Brisant
The UK's highest-rated cylinder. Patent-protected key. £1,000 guarantee if your home is broken into via the lock. Hidden inner core activates if snapping is attempted.
TS007 3★ · SS312 Diamond · 10-Year Guarantee
Avocet ABS
Features a magnetic key element that's virtually impossible to copy. Extremely resistant to snap, pick, and bump attacks. Popular with South London homeowners and landlords.
TS007 3★ · SS312 Diamond · Anti-Copy Key
Mul-T-Lock MT5+
Multi-layer pin system makes picking virtually impossible. Preferred for commercial properties and high-value residential. Keys can only be copied at authorised dealers.
TS007 3★ · SS312 Diamond · Patent-Protected
Can a Euro Cylinder Be Snapped — and How Do You Protect Against It?
Yes — and it's the most common method used in South London burglaries. Cylinder snapping involves applying force to the protruding end of the cylinder to break it at the manufactured snap point, exposing the cam mechanism. The whole process takes under 10 seconds and requires no locksmith skill.
Anti-snap cylinders like the Ultion and Avocet ABS have a redesigned snap point that breaks safely — the fragment that snaps off doesn't expose the cam. The lock remains secure even after the attack. This is what TS007 certification specifically tests for.
Euro cylinder locks — understanding your size and security rating is essential for home protection
If you're unsure whether your current cylinder is anti-snap rated, our engineers can assess it free of charge when attending any job. We always recommend upgrading to a 3-star cylinder if your door currently has a standard OEM cylinder — which is the case for most doors installed before 2018.
How Much Does Euro Cylinder Replacement Cost in South London?
Replacing a euro cylinder in South London starts from £135, which includes the cost of a premium TS007 3-star cylinder, labour, and a 12-month workmanship guarantee. We carry all common sizes (35/35, 40/40, 35/45, 40/50) and can usually complete the job on the same visit.
From £135
Single Cylinder
Supply + fit TS007 3-star
From £200
2 Cylinders
Front + back door package
Free
Security Assessment
During any attended job
All prices are fixed and quoted before work begins. No call-out fee. No hidden extras. We cover all South London postcodes — SE1 to SE27, SW2 to SW20, CR0 to CR9, SM1 to SM6, and BR1 to BR6.
South London Locksmith
Ready to Upgrade Your Euro Cylinder?
TS007 3-star anti-snap cylinders, fitted same day. Fixed price, no call-out fee.
Frequently Asked Questions — Euro Cylinder Locks
What is a euro cylinder lock?
A euro cylinder lock is the most common type of lock used in uPVC, composite, and aluminium doors across the UK. It is a cylinder-shaped mechanism fitted into the door handle backplate, operated by a key from outside and a thumb-turn from inside. The security level varies widely — standard cylinders offer minimal protection, while TS007 3-star cylinders resist snapping, picking, drilling, and bumping.
How do I measure a euro cylinder?
Measure from the centre of the fixing screw hole to each end of the cylinder. The format is written as exterior × interior (e.g. 35/45 = 80mm total). Remove the handle to access the cylinder, undo the grub screw on the door edge, turn the key slightly, and slide the cylinder out. Getting the right size is critical — too much protrusion on the external side creates a snap risk.
What star rating euro cylinder should I choose?
For residential properties in South London, we recommend a minimum TS007 3-star cylinder. This provides the highest level of protection against snapping, picking, drilling, bumping, and extraction. Brands like Ultion, Avocet ABS, and Mul-T-Lock all hold both TS007 3-star and Sold Secure Diamond certification. Many insurers now specify at least a 1-star TS007 cylinder as a policy condition.
Can euro cylinders be snapped by burglars?
Yes — standard euro cylinders can be snapped in under 10 seconds using basic tools. Burglars break off the protruding end to expose the internal cam mechanism. Anti-snap cylinders counter this with a sacrificial snap line that breaks safely, keeping the lock secure after the attack. This is the primary feature tested under the TS007 standard. All cylinders we supply and fit are anti-snap rated.
How much does euro cylinder replacement cost in South London?
Euro cylinder replacement in South London starts from £135, including supply and fitting of a TS007 3-star anti-snap cylinder with a 12-month workmanship guarantee. We carry all common sizes (35/35 to 50/55) and can complete the replacement on the same visit. No call-out fee, and all prices are quoted upfront. We cover all South London postcodes: SE, SW, CR, SM, and BR.
Our Locksmith
Professional Locksmiths · South London
Our team of qualified locksmiths has been serving South London for over 10 years. We specialise in high-security lock installations, euro cylinder upgrades, and residential security assessments. Every recommendation in this guide is based on cylinders we install and test daily across SE, SW, CR, SM, and BR postcodes.
Related Guides
Lock Standards
British Standard Locks Explained
What BS3621 means, why insurers require it, and which locks qualify.
Insurance Guide
Do You Need BS3621 for Insurance?
How lock specifications affect your home insurance validity in the UK.
Security Guide
Anti-Snap Locks Explained
Why cylinder snapping is the most common South London break-in method.
South London Locksmith
Need Your Euro Cylinder Upgraded Today?
TS007 3-star anti-snap cylinders, fitted same day across South London. Fixed price, no call-out fee, 12-month guarantee.
24/7 emergency locksmith serving South London since 2015 — trusted by homeowners, landlords and businesses across Sutton, Mitcham, Wallington, Cheam, Purley and surrounding areas.