Why Security Ratings Exist
Walk into any hardware store and you'll find locks labeled "high security," "heavy duty," or "commercial grade." Without an independent standard, these labels mean nothing — every manufacturer would simply call their products the best. Security ratings from independent standards bodies give you a consistent, testable way to compare locks across brands.
ANSI/BHMA Grades (North America)
The American National Standards Institute (ANSI) and the Builders Hardware Manufacturers Association (BHMA) jointly maintain the most widely used residential and commercial lock rating system in North America. Locks are tested under ANSI/BHMA A156 standards, which cover dozens of hardware categories.
The Three Grades
| Grade | Use Case | Cycle Test | Strike Test |
|---|---|---|---|
| Grade 1 | Commercial / High-Security Residential | 250,000 cycles | 10 strikes at 75 ft-lbs |
| Grade 2 | Heavy Residential / Light Commercial | 150,000 cycles | 5 strikes at 75 ft-lbs |
| Grade 3 | Standard Residential | 100,000 cycles | 2 strikes at 75 ft-lbs |
The "cycle test" simulates the lock being operated over its lifetime. The "strike test" measures resistance to kick-in force. Both are conducted by independent testing labs — manufacturers cannot self-certify for ANSI grades.
What ANSI Doesn't Test
ANSI grades test durability and basic forced entry resistance — they do not specifically test resistance to picking, bumping, or drilling. A Grade 1 lock is not automatically pick-resistant. For those properties, look for additional certifications or manufacturer disclosures about security pin configurations.
UL Listings (Underwriters Laboratories)
UL is best known for electrical safety, but it also certifies locks and safes. For residential and commercial locks, the most relevant UL standard is:
- UL 437 (Key Lock): Covers resistance to picking, drilling, pulling, and torque attacks. A UL 437 listing is a strong indicator of a high-security cylinder. Locks achieving this are sometimes called "UL Listed" cylinders.
UL certification is voluntary and independently verified. It's a meaningful mark, especially for high-security applications.
CEN Grades (Europe)
In Europe, locks are rated under European Standard EN 1303 (cylinders) and EN 12209 (mortise locks), with a scale from Grade 1 (lowest) to Grade 6 (highest):
- Grade 1–2: Low security, interior use.
- Grade 3–4: Standard residential exterior use.
- Grade 5–6: High security, certified resistant to picking and drilling. Often required by insurers for certain property types.
European insurance policies sometimes mandate a minimum CEN grade for lock coverage to apply — worth checking if you're insuring a property in Europe.
Sold Secure and Similar Independent Ratings
Beyond government and standards-body certifications, several independent testing organizations publish their own ratings:
- Sold Secure (UK): Tests padlocks, chains, and cycle locks against attack. Bronze, Silver, and Gold ratings based on resistance time and attack type. Widely referenced by UK insurers.
- ART Foundation (Netherlands): Popular for bicycle and motorcycle security; tests complete security solutions, not just individual locks.
How to Use Ratings Practically
- Start with ANSI Grade 1 for any exterior door lock. It's the baseline for serious residential security.
- Add UL 437 for high-value properties or when pick/drill resistance is a concern — commercial buildings, vacation homes, storage units.
- Check your insurer — some home insurance policies specify minimum lock grades. Non-compliance can affect claims.
- Don't rely solely on ratings — the lock is one part of the system. Door frame, hinges, and strike plate all matter equally.
The Locksmith's Perspective
Experienced locksmiths tend to focus less on marketing claims and more on the manufacturer's transparency. Brands that publish their cylinder specifications, security pin details, and testing data are generally more trustworthy than those that rely purely on vague "high security" language. Ratings are your starting point — not the final word.