Anti-Snap Lock Upgrades

A Burglary Method That Takes Seconds

Lock snapping is deceptively simple. A burglar inserts a tool — a screwdriver, a pair of mole grips — into the outer section of a Euro cylinder lock. The exposed part of the cylinder snaps off cleanly, revealing the inner cam that controls the mechanism. A flathead screwdriver is then all that is needed to turn the cam and open the door. The whole process can take under ten seconds. The door's multipoint locking system, with its multiple hooks and bolts, is bypassed entirely because the cylinder — the component that controls all of it — has been defeated.

This vulnerability affects any property with a standard Euro cylinder in a UPVC or composite door. That encompasses the majority of UK housing built since the 1990s.

The Standard to Look For: TS007

TS007 is a British Standard specifically developed to address the lock-snapping vulnerability. It tests cylinders against snapping, drilling, picking, bumping, and extraction. Cylinders are rated on a star system:

• 1-star: The cylinder alone meets the standard. Provides basic anti-snap protection.
• 3-star cylinder: The highest individual cylinder rating. Provides anti-snap, anti-drill, anti-pick, anti-bump, and anti-extraction protection.
• Combined rating: A 1-star cylinder paired with a 2-star door handle also achieves the 3-star overall requirement.

West Yorkshire Police specify that a 3-star TS007 cylinder is the preferred option, with 3 stars overall being the minimum recommended standard. Sold Secure Diamond (SS312) accreditation is an equivalent standard from the independent Sold Secure testing body.

How Anti-Snap Cylinders Work

An anti-snap cylinder has a designed weak point — a sacrificial section engineered to break at a point that does not compromise the inner mechanism. If a burglar attempts to snap the cylinder, the outer section does break away — but the inner section remains functional and includes its own security measures that prevent the cam from being turned without a key. The burglar is left with a piece of broken cylinder and a door that remains locked.

The engineering matters. Not all cylinders sold as "anti-snap" carry TS007 accreditation. Some cheaper cylinders use the marketing term without independent testing. When specifying a cylinder, ask the locksmith to confirm the TS007 rating and the star level, or check the cylinder's packaging for the British Standards Kitemark.

Cylinder Sizing: Why Getting It Right Matters

Euro cylinders are measured by the distance from each end to the centre (where the cam sits). A common size is 35/45mm — 35mm on the inside of the door, 45mm on the outside. If the cylinder protrudes more than 3mm beyond the door furniture (the handle and escutcheon), it is more vulnerable to snapping; a cylinder that sits flush or slightly recessed is harder to grip. Your locksmith should measure the existing cylinder before ordering a replacement.

Insurance Compliance

Many UK home insurers now specify TS007 3-star cylinders (or equivalent) as a policy condition for UPVC and composite doors. Check your policy schedule before purchasing a replacement cylinder. If your existing cylinder is standard and your insurer specifies TS007, you may technically be outside your policy terms — worth resolving before you need to make a claim rather than discovering it afterwards.

Our Watch (the Neighbourhood Watch national body) advises homeowners to check whether door locks meet BS3621 for timber doors and to look for the British Standard Kitemark engraved on the lock body as confirmation of compliance.