Anti-snap euro cylinders: TS 007 3-star vs Sold Secure SS312 Diamond

If you have a uPVC or composite front door, there’s a good chance your security depends on one small part: the euro cylinder, the bit you put your key into. Many cylinders fitted over the years are vulnerable to a technique called lock snapping. Here’s how it works, what the ratings mean and how to choose a replacement.

What is lock snapping?

A euro cylinder is a long, profile-shaped barrel held in the door by a single screw through its middle. Under that screw is its thinnest, weakest point. In a lock-snapping attack, a burglar applies force to the part of the cylinder sticking out of the door until it snaps at that weak point. With the outer half gone, they can reach the cam inside and operate the lock. On a vulnerable cylinder this can take less than a minute, and it makes little noise.

It doesn’t matter how many hooks and bolts your multipoint lock has. If the cylinder can be snapped, they can all be opened.

Is my cylinder vulnerable?

Signs that your cylinder may be a basic, non-rated type:

• no markings near the keyhole, or just a brand name
• the cylinder sticks out several millimetres past the handle or escutcheon
• it was fitted with the door years ago and never changed
• the keys are plain, cheap-looking blanks that can be copied anywhere

Rated cylinders usually have a Kitemark and star symbols, or a Sold Secure marking, on the face near the keyhole.

TS 007: the Kitemark star system

TS 007 is a British Kitemark scheme for door hardware. It uses stars:

• 1-star cylinder. Basic attack resistance. It needs to be paired with 2-star security handles to reach a 3-star rating.
• 3-star cylinder. Resists snapping, drilling, picking and bumping on its own, without special handles.

So you can reach a 3-star overall rating either with a 3-star cylinder, or with a 1-star cylinder plus 2-star handles. The 3-star cylinder route is usually simpler, because it doesn’t depend on the handles staying in good condition.

Sold Secure SS312 Diamond

Sold Secure is a testing house owned by the Master Locksmiths Association. Its SS312 Diamond standard is widely regarded as one of the toughest tests for euro cylinders, because the attacks are carried out by skilled locksmith testers using the techniques burglars actually use, including snapping, picking, bumping and drilling. Cylinders that pass are marked SS312 Diamond.

Many high-quality anti-snap cylinders carry both TS 007 3-star and SS312 Diamond.

Which is better?

Either is a big step up from an unrated cylinder. In practice:

• TS 007 3-star is the rating most insurers and door manufacturers mention.
• SS312 Diamond is a tougher, attack-based test and a strong signal of quality.
• A cylinder with both gives you the most confidence.

Beyond the attack ratings, consider key control. High-security cylinders such as Mul-T-Lock use registered or patented keys, so copies can only be cut through authorised dealers on proof of ownership. Moray Locksmith is an approved distributor and stockist of Mul-T-Lock high-security cylinders.

Measuring your cylinder

Euro cylinders come in many lengths, and the fit matters. A cylinder that sticks out is easier to attack, while one that is too short may not work properly. Cylinder sizes are given as two measurements from the centre of the fixing screw to each end, for example 40/45 (40mm outside, 45mm inside).

To measure:

1. Open the door and find the fixing screw on the edge of the door, in line with the cylinder.
2. Measure from the centre of the screw to the outside end of the cylinder, then to the inside end.

A locksmith will measure and fit it properly, setting the cylinder so it’s flush, or nearly flush, with the outside handle.

Thumb-turn or key on both sides?

Many people like a thumb-turn on the inside, so you can unlock without a key in an emergency. It’s safer for escape, but think about whether the thumb-turn could be reached through a glass panel or letterbox. Anti-snap thumb-turn cylinders are widely available.

Other improvements to make at the same time

• Security handles with a cylinder guard, which shroud the cylinder.
• Door alignment and a mechanism service, so the new cylinder isn’t fighting a dropped door. See uPVC door problems.
• Keyed alike. Front and back doors can use the same key.

Is it worth it?

For most homes, replacing a basic cylinder with a rated anti-snap one is among the best-value security upgrades available. It’s usually a short job and it closes off one of the most common ways into uPVC-doored homes. It may also help you meet your insurer’s requirements. Read BS 3621 explained.

Key points

Basic euro cylinders can be snapped quickly. Look for TS 007 3-star or Sold Secure SS312 Diamond, ideally both, and get the cylinder sized correctly. In Moray, Moray Locksmith fits anti-snap and high-security cylinders.

This guide is general information for homes in Scotland. It is not legal or insurance advice. Always check your own policy, tenancy agreement and official guidance.