TS007 3-Star vs SS312 Diamond: Lock Security Standards Decoded

TS007 vs SS312 vs Secured by Design: Lock Standards Explained

Lock security standards are confusing. Manufacturers throw around terms like "3-star", "Diamond Standard", and "Secured by Design" as if everyone knows what they mean. Most people don't, and that's not their fault — the system is genuinely complicated.

I'm Albert, a locksmith in Coventry, and I'm going to break down the three main standards you'll encounter when shopping for door locks in the UK. By the end of this, you'll know exactly what each one means and which standard matters for your specific situation.

TS007: The Star Rating System

TS 007-1:2024+A1:2026 is a Door & Hardware Federation technical specification for replacement cylinders and associated security hardware. It uses a star-rating system and is commonly referenced when comparing anti-snap cylinders for uPVC and composite doors. A product-specific BSI Kitemark certificate number is not the name of the standard.

How the Star System Works

This is where it gets interesting — and where most people get confused.

1-Star: A component (cylinder, handle, or escutcheon) that provides a basic level of attack resistance on its own.

2-Star: A component that provides a higher level of attack resistance on its own.

3-Star: This is the target. A 3-star rating means the total door lock assembly provides the highest level of protection against common attacks including snapping, bumping, picking, and drilling.

The Critical Point: 3 Stars Is the Target

Here's what trips people up: you need the components to add up to 3 stars total. There are several ways to achieve this:

What Attacks Does TS007 Test For?

The TS007 testing regime subjects the lock assembly to:

The test simulates real-world attack methods with specific time limits and force levels. A component earns its star rating based on how long it resists these attacks.

TS007 in Practice

When I fit an anti-snap cylinder, the conversation about TS007 usually goes like this:

Customer wants maximum security and is happy to pay for it:

I fit an Ultion (3-star standalone). Job done — one cylinder, full 3-star protection.

Customer wants good security at a reasonable price:

I fit an Avocet ABS or ABS MK3 (1-star cylinder) with a 2-star security handle. Total = 3 stars. This combination costs less than an Ultion and provides the same certified level of protection.

Customer wants to upgrade but is on a tight budget:

I fit a 1-star anti-snap cylinder. This is significantly better than no anti-snap protection at all, even though it doesn't reach the 3-star total alone. We can add a security handle later.

SS312: Sold Secure Diamond

SS312 is a specification administered by Sold Secure, an independent testing organisation. Its Diamond grade is for standalone high-security cylinders. The current SS312:2024 specification includes cylinder attack tests beyond snapping, so it should not be described as a snap-only test.

What SS312 Tests For

The SS312 test includes attack resistance for the standalone euro cylinder, including:

A cylinder that passes receives the Sold Secure Diamond standard (sometimes written as SS312 Diamond).

How SS312 Relates to TS007

The two specifications overlap but certify products independently:

A cylinder can hold both certifications, but passing one does not mean it automatically holds the other. Check the exact model in the current certification catalogue rather than relying on a brand-wide claim.

Both are useful independent signals. The right choice depends on whether you are replacing the cylinder alone or assessing the cylinder together with protective door hardware.

Secured by Design

Secured by Design (SBD) is a police-backed initiative run by Police Crime Prevention Initiatives Ltd. It's not a testing standard in itself — it's an accreditation scheme that recognises products meeting relevant security standards.

What "Secured by Design" Means

A product listed by Secured by Design has been accepted under the scheme's current criteria. Check the exact product listing and any conditions or compatible components rather than inferring a particular star rating from the logo alone.

The SBD Logo

The Secured by Design mark may appear on products or supporting material. Confirm that the exact model or complete doorset is in the current scheme listing.

How SBD Relates to TS007 and SS312

They are different evidence layers:

Do not infer one certification from another. Verify the exact model in each relevant current catalogue and assess the lock with its compatible door hardware.

Which Standard Matters for You?

If You Have a uPVC or Composite Door

Look for an exact cylinder or certified cylinder-and-furniture combination with a current independent rating relevant to recognised attacks. Sold Secure's live lock-cylinder database is updated as listings change. Read my anti-snap locks comparison for the checks to make before choosing a model.

If You Have a Wooden Door

The relevant standard for you is BS3621 for your mortice deadlock. TS007 and SS312 apply to euro cylinders, which aren't typically found on wooden doors.

If your wooden door does have a euro cylinder (some modern wooden doors do), then the TS007 and SS312 standards apply to that cylinder.

If You're Insurance-Conscious

Some insurance policies reference BS3621 for wooden doors, while others use different security wording. For uPVC doors, check the exact policy requirements before treating any star rating as mandatory.

Secured by Design accreditation is separate evidence to verify for the exact product; it does not establish what an insurer requires or how a claim will be decided.

For New Build Properties

If you're buying a new build in Coventry, check the supplied doorset documentation and exact lock markings. If the evidence or fit is unclear, have the complete door assessed before deciding whether an upgrade is needed.

Common Misunderstandings

"My lock says 'anti-snap' so it must be certified"

Not necessarily. Any manufacturer can call their product "anti-snap" — it's a description, not a certification. What matters is whether it carries TS007 or SS312 certification from an independent testing body. Always look for the Kitemark or Sold Secure logo.

"3-star is always better than 1-star"

A 3-star cylinder is better tested than a 1-star cylinder on its own, yes. But a 1-star cylinder with a 2-star handle gives you the same 3-star total protection at a potentially lower cost. The stars are about the total assembly, not just the individual component.

"I need all three standards"

Not really. If your euro cylinder has TS007 3-star (or equivalent combination) and SS312 Diamond, you're well covered. Secured by Design is a bonus but not essential for home security.

"Higher price means better security"

Not always. Price reflects brand positioning, manufacturing costs, and margin — not just security. Some mid-range cylinders with full certification outperform expensive but uncertified alternatives. Check the certifications, not just the price tag.

The Bottom Line

For a uPVC or composite door in Coventry, fit a euro cylinder that is:

That's it. Don't get lost in the alphabet soup of standards. If a cylinder meets those two criteria, it's providing genuine, independently tested protection for your home.

If you want advice on which certified lock is right for your door, call me on 024 7522 4730. The door, required cylinder dimensions, certification and current product availability must be checked before the fitting date or number of visits can be confirmed. See the prices page for current rates on lock changes and upgrades.

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