Anti-Snap Cylinders Explained: TS007 3-Star & SS312 Diamond
If you have a uPVC or composite front door, the security of your whole home often rests on one small component: the Euro cylinder. Older cylinders are vulnerable to a quick, quiet attack called lock snapping, and upgrading to a properly rated anti-snap cylinder is one of the cheapest, highest-impact security improvements you can make. Here is how the ratings work and what to look for.
What is lock snapping?
Lock snapping is a forced-entry method that targets the standard Euro profile cylinder fitted to most uPVC and composite doors. An intruder grips the part of the cylinder that protrudes past the handle, applies pressure, and snaps it across a deliberately weak point. Once the front section breaks away, the internal cam can be manipulated and the door opened in under a minute, often with everyday tools and very little noise.
The problem is that millions of doors still carry basic, uncertified cylinders. The good news is that the lock industry has responded with hardened, sacrificial designs that defeat the attack.
How anti-snap cylinders defend the door
A genuine anti-snap cylinder uses one or more engineered features:
- Sacrificial snap lines that break off harmlessly, leaving the working core intact and the door still locked.
- Hardened steel pins and anti-drill plates that resist drilling and picking.
- Anti-bump pins to defeat key bumping.
- Reinforced cores that keep the cam protected even under heavy force.
Reading the two ratings that matter
TS007 3-star
TS007 is the British kitemark scheme run with the Door and Hardware Federation and the Glass and Glazing Federation. It uses a star system. A 3-star cylinder passes anti-snap, anti-pick, anti-bump and anti-drill tests on its own. Alternatively, you can reach the same protection with a 1-star cylinder paired with a 2-star security handle or escutcheon — the stars add up to three. Always aim for three stars in total.
SS312 Diamond (Sold Secure)
The Sold Secure Diamond standard, SS312, is widely regarded as the toughest cylinder test in the UK. It includes a brutal snapping and manipulation regime, so a cylinder carrying the Diamond mark has been independently proven to resist the most common attacks. Many top-tier cylinders hold both TS007 3-star and SS312 Diamond accreditation.
Measuring and fitting
Euro cylinders are sized in millimetres from the central fixing screw to each end (for example 35/45). A cylinder that sticks out more than a few millimetres past the handle gives an attacker something to grip, so correct measurement is essential — an over-long cylinder undermines even a good rating. Because of this, professional measurement and fitting is well worth it. Our guide to lock replacement and installation explains how a properly sized, anti-snap cylinder is fitted to a multipoint door.
Why it matters for your insurance and your peace of mind
Upgrading a vulnerable cylinder is far cheaper than dealing with the aftermath of a break-in. If your home has already been targeted, fast burglary repairs and property boarding can secure the door the same day, and a 3-star cylinder fitted afterwards reduces the chance of a repeat attempt.
A quick self-check
- Does your cylinder protrude past the handle? If so, it is a target.
- Can you see a kitemark or star rating stamped on the key or cylinder? If not, assume it is unrated.
- Is the door uPVC or composite with a multipoint lock? These almost always use a Euro cylinder you can upgrade independently.
If you are unsure what is fitted, a locksmith can identify the cylinder in minutes and recommend the right TS007 3-star or SS312 Diamond replacement for your door across Birmingham and Erdington.