GUIDE

High Security Cylinders Explained: A Complete Technical Guide

Everything you need to know about high-security Euro cylinders. Anti-snap, anti-drill, anti-pick features explained with buying recommendations.

The cylinder is the heart of your Euro lock system. It’s the component criminals target, the part that determines whether your door holds or yields. Understanding cylinder technology transforms you from passive consumer to informed decision-maker.

What Is a Euro Cylinder?

The Euro cylinder is the removable, key-operated portion of your lock mechanism. When you insert your key, it turns the cylinder, which rotates a cam that retracts the door’s locking bolts.

Why Cylinders Are Targeted

Euro cylinders offer criminals a convenient attack point because:

  • They protrude from the door surface
  • Standard versions are structurally weak
  • Attack techniques are simple to learn
  • Success takes seconds, not minutes

The Anatomy of Attack Resistance

Anti-Snap Protection

The attack: A criminal applies rotational force to the exposed cylinder using pliers or a specialized tool. The cylinder breaks at its weakest point—usually where the fixing screw connects.

The defence: Anti-snap cylinders incorporate sacrificial cut lines—engineered weak points near the front of the cylinder. When attacked, the cylinder breaks at this predetermined location, leaving only a useless fragment in the criminal’s hand while the main mechanism remains secure and locked.

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Anti-snap doesn’t prevent snapping—it controls where the break occurs, ensuring the lock remains functional and secure.

What to look for:

  • Clearly marked snap lines
  • Correct sizing (minimal protrusion beyond door furniture)
  • Tested and certified protection

Anti-Drill Protection

The attack: Drilling through the cylinder to reach and manipulate the internal mechanism.

The defence: High-security cylinders contain hardened steel pins or plates positioned to destroy drill bits before they can penetrate critical areas. Some cylinders feature multiple anti-drill pins at different angles.

What to look for:

  • Anti-drill pins visible through the keyway
  • Certification confirming drill resistance
  • Hardened steel components (not just marketing claims)

Anti-Pick Protection

The attack: Using specialised tools to manipulate individual pins inside the lock, simulating the action of the correct key.

The defence: Premium cylinders use anti-pick pins with unusual shapes, serrations, or spool designs that make manipulation extremely difficult. The number and configuration of pins determines pick resistance.

What to look for:

  • Minimum 6 pins, preferably more
  • Complex pin profiles
  • Anti-pick certification

Anti-Bump Protection

The attack: “Bumping” uses a specially cut “bump key” and sharp impact to momentarily jump the pins, allowing the lock to open.

The defence: Anti-bump cylinders feature specially designed pins that don’t respond to bump attacks. Some use magnetic systems or other technologies that are completely bump-proof.

What to look for:

  • Explicit anti-bump rating
  • Non-standard pin systems
  • Tested certification

Anti-Extraction Protection

The attack: After snapping the front section, the criminal inserts a tool to pull out the remaining cylinder piece.

The defence: Retention mechanisms hold the cylinder stub in place even after a snap attack, preventing extraction and maintaining security.

What to look for:

  • Anti-extraction features mentioned specifically
  • Tested post-snap security

Understanding Security Ratings

TS007 Star Rating System

The British Standard for enhanced security cylinders uses a star rating system:

RatingDescription
1-StarEnhanced cylinder security (use with 2-star door hardware)
2-StarEnhanced door hardware security
3-StarComplete integrated solution—all necessary protection in one unit

Sold Secure Ratings

An independent testing organisation that evaluates security products:

RatingSecurity Level
BronzeBasic enhanced security
SilverGood resistance to attack
GoldHigh resistance, recommended for most homes
DiamondMaximum tested resistance

Kitemark and BSI

The BSI Kitemark indicates the product meets British Standards. For cylinders, look for BS EN 1303 compliance alongside TS007.

Sizing Your Cylinder

Correct sizing is crucial for security. A cylinder that protrudes excessively from the door furniture provides leverage for attack.

Measuring for Replacement

  1. Remove your existing cylinder (turn key to 45°, unscrew fixing bolt, withdraw cylinder)
  2. Measure from center of fixing screw hole to each end
  3. Note the measurements as “inside x outside” (e.g., 40/45)

Common Sizes

Most UK doors use cylinders between 70mm and 110mm total length. The external (outside) measurement is typically 5-10mm longer than the internal.

Key Control and Restricted Profiles

What Is Key Control?

Key control means controlling who can copy your keys. Standard keys can be duplicated at any high-street shop. Restricted keys require:

  • Proof of ownership
  • A security card unique to your lock
  • Ordering through authorised channels

Why It Matters

If anyone can copy your key, your security depends entirely on physical key custody. With restricted keys, even if someone temporarily accesses your key, they cannot easily create a copy.

Levels of Key Control

LevelProtection
BasicStandard keys, easily copied anywhere
RegisteredKeys with unique cuts, copied at authorised dealers
RestrictedKeys protected by patent, require security card
High-SecurityMulti-layer verification, typically commercial grade

Features to Prioritise

Essential (Non-Negotiable)

  • TS007 3-star rating OR 1-star with 2-star handle
  • Anti-snap protection
  • Anti-drill protection
  • Correct sizing for your door
  • Anti-pick with 6+ pins
  • Anti-bump certification
  • Anti-extraction features
  • Reputable manufacturer

Premium

  • Restricted key system
  • Key card protection
  • Sold Secure Diamond rating
  • 10+ pin systems
  • High-grade materials throughout

For complete recommendations, see our guide on choosing the right lock.

Common Mistakes to Avoid

Mistake 1: Buying on Price Alone

“Anti-snap” is a marketing term anyone can use. Budget cylinders may claim protection but fail under actual attack. The difference between a £30 and £100 cylinder is the difference between vulnerable and protected.

Mistake 2: Incorrect Installation

Even the best cylinder fails if:

  • It protrudes excessively
  • The fixing screw is weak or wrong size
  • The door furniture isn’t compatible
  • Other door components are neglected

Mistake 3: Ignoring the Full System

A premium cylinder in a weak door, or protected by flimsy handles, offers incomplete security. The system is only as strong as its weakest component.

Mistake 4: Choosing Based on Features Alone

A cylinder with every feature but no certification might be inferior to a certified product with fewer claimed features. Trust independent testing over marketing lists.

Installation Considerations

DIY vs Professional

Replacing a Euro cylinder is one of the simpler locksmith tasks:

DIY is appropriate when:

  • You’re replacing a basic cylinder with another
  • You can accurately measure your door
  • You’re comfortable with basic tools

Professional fitting recommended when:

  • You need precise sizing recommendations
  • You’re upgrading multiple doors (economies of scale)
  • You want installation warranty and verification
  • Your insurance requires professional fitting documentation

What Proper Fitting Includes

  1. Accurate measurement and cylinder selection
  2. Verification of door furniture compatibility
  3. Correct screw sizing and security
  4. Testing operation from both sides
  5. Key programming for restricted systems (if applicable)
  6. Old cylinder disposal

Maintenance and Longevity

How Long Do Quality Cylinders Last?

A well-made cylinder should function reliably for 10-15 years with minimal care. Signs of aging include stiffness, key resistance, and difficulty turning.

Basic Maintenance

  • Lubricate annually with graphite powder or specialist lock lubricant (not WD-40)
  • Keep keys clean of debris that can transfer into the mechanism
  • Check protrusion hasn’t changed due to door settling
  • Test operation periodically—problems develop gradually

Frequently Asked Questions

What does TS007 3-star rating mean?

TS007 is the British Standard for enhanced security cylinders. A 3-star rating means the cylinder is a complete integrated solution providing anti-snap, anti-drill, anti-pick, and anti-bump protection in one unit.

Is anti-snap protection really necessary in the UK?

Yes. Lock snapping is responsible for approximately 27% of UK burglaries. Insurance policies increasingly require anti-snap protection. The small additional cost provides substantial security improvement.

How much should I pay for a high-security cylinder?

Expect to pay £80-150 for a genuine high-security cylinder from a reputable manufacturer. Budget cylinders claiming anti-snap at £30-50 often fail under real attack conditions.

Can I fit a high-security cylinder myself?

Yes, if you can accurately measure your door and handle basic tools. Turn the key to 45°, unscrew the fixing bolt, and swap cylinders. However, measurement mistakes are common—when in doubt, get professional fitting.

What brands are reliable for high-security cylinders?

Look for established manufacturers with verified testing history: Avocet ABS, Ultion, Mul-T-Lock, Yale Superior, Brisant. Avoid unknown brands regardless of claimed features.

Does a high-security cylinder work with my existing door?

In most cases, yes. Euro cylinders are standardised—a quality replacement should fit your existing multipoint lock mechanism. Only sizing changes, not the fundamental design.

How can I verify a cylinder is genuine?

Purchase from authorised dealers, check for consistent branding on packaging and the cylinder itself, verify any security card or registration system works, and look for certification marks.

What is anti-snap protection and how does it work?

Anti-snap cylinders have engineered sacrificial cut lines near the front. When attacked, the cylinder breaks at this predetermined location, leaving only a useless fragment while the main mechanism remains secure.

Investment Perspective

Consider this: the average UK burglary results in over £3,000 of losses and damage. The emotional impact is incalculable. A premium cylinder costs £80-150 and lasts over a decade.

The mathematics are simple. The return on investment is enormous. And unlike insurance, a quality cylinder prevents the loss rather than merely compensating for it.

Written by Trulox Security Experts

Trusted security experts committed to protecting what matters most.

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