LPS 1175 F10 (SR6) Security Rating Explained

LPS 1175 F10, the Issue 8 rating commonly compared with SR6, certifies that a complete product has resisted a professional, multi-person attack using mains-powered saws and grinders and oxyacetylene cutting equipment for at least ten minutes. It is a specialist rating for high-security government buildings, defence sites and the most critical areas of national infrastructure. This guide explains what F10 means, how it differs from E10 and SR6, and how to specify and verify an F10 product.

What Does LPS 1175 F10 Mean?

LPS 1175 is the Loss Prevention Standard for intruder resistant building components, published by the Loss Prevention Certification Board (LPCB), part of BRE Global. Every Issue 8 rating has two parts: the letter sets the tools and the attack scenario, and the number sets the minimum delay in minutes the product must achieve.

At F10, the test team attacks the locked product with Category F tools and must not create a 400 mm x 225 mm opening, the minimum size a person can climb through, within ten minutes of working time. Any part of the assembly can be targeted, including frames, infill panels, glazing, locks, hinges and fixings.

The Category F tool set

Category F represents a professional, well-resourced team with access to mains power, prepared to make a great deal of noise. The kit includes everything in Categories A to E plus:

• Categories A to E: hand tools, bolt cutters, an axe, a crowbar, a gas torch, sledgehammers, and 18V and 36V cordless saws and grinders
• Added at Category F: mains-powered saws and grinders rated over 2000W, and an oxyacetylene cutting kit
• Attack scenario: more than one attacker working on the product at the same time

Mains-powered tools do not run down like batteries, cut harder and faster than cordless equivalents, and oxyacetylene equipment can cut through thick steel. Combined with several attackers working together, that makes Category F a step change from E10 rather than an incremental one.

F10 vs SR6: Issue 8 and Issue 7 Explained

LPS 1175 Issue 8 came into effect in 2019 and was the most substantial revision of the standard to date. It replaced the single SR1 to SR8 scale with a tool category letter (A to H) followed by a minimum delay in minutes (1, 3, 5, 10, 15 or 20). F10 is the Issue 8 classification commonly compared with the old SR6.

The letters can be confusing when moving between the two issues. Issue 7 used an enhanced Category D kit, written D+, for SR5. Issue 8 turned that kit into Category E, so every tool category above it moved up a letter: the Issue 7 tool set behind SR6, which was called Category E, corresponds to Issue 8 Category F. When comparing older documents with new ones, compare the rating, not just the letter.

What F10 Means for Design and Installation

At F10, the product is only one part of the protection. A rating this high is usually specified as part of a wider security design, and several factors around the product decide whether the certified delay is achieved in practice:

• Substrate and fixings: the wall, slab or foundation around the product needs equivalent attack resistance. A certified F10 door in a weaker wall simply moves the attack to the wall.
• Access to mains power: Category F assumes the attacker can power heavy tools. Consider how external sockets and supplies near protected openings are controlled.
• Detection and response: the delay only has value if an attack is detected early and a response arrives within it. Match the rating to the response time set in the threat assessment.
• Layered protection: perimeter barriers, building envelope and internal secure rooms each add delay and a chance to detect the attack. Each layer keeps its own rating; ratings do not add together on a certificate.

Where F10 Is Specified

F10 is specified where the credible threat is a professional, well-resourced team and a breach would have severe consequences for national security, public safety or critical services. Typical applications include:

• High-security government buildings
• Defence and military sites
• Critical national infrastructure control areas
• Strongrooms and secure stores
• High-risk embassies and diplomatic sites
• Critical data and communications facilities

A rating at this level should always come from a formal threat assessment. In government and critical infrastructure contexts, that assessment is typically informed by NPSA (National Protective Security Authority) guidance, and it will set the attacker profile, the response time and therefore the rating required for each layer.

Specifying an F10 Product: Checklist

• Confirm the product holds an LPCB certificate showing F10 under Issue 8 (both the letter and the number), and check the current listing on Red Book Live
• Check that the certificate covers the exact configuration, size and opening direction being specified
• Use only the locking systems listed on the certificate; other locks do not carry the rating
• Design the surrounding wall, slab or foundation to match the attack resistance of the product
• Detail fixings and the connection to the structure, which sit outside the certificate
• Align the delay with the detection and response plan in the threat assessment
• Plan an uninterrupted power supply for powered locking and access systems if the rating must hold during a mains failure
• Remember that resistance of access control systems to non-mechanical attack is outside the scope of LPS 1175

Frequently Asked Questions: LPS 1175 F10 and SR6

Related Premier Security Resources

• LPS 1175 Security Ratings Explained: the full SR1 to SR8 and A1 to H20 guide
• LPS 1175 E10 / SR5 Rating Guide: the rating below F10
• LPS 1175 D10 / SR4 Rating Guide: the Category D power tool rating
• Ballistic Resistance: EN 1522 FB and EN 1063 BR ratings explained
• Blast Resistance: ISO 16933, EN 13123 and EN 13541 ratings explained
• Hostile Vehicle Mitigation: protection against vehicle borne threats
• Contact Premier Security: technical consultation and project enquiries