High-Security Lock Comparison Reference
Why this matters
High-security locks provide protection against picking, drilling, bumping, and unauthorized key duplication. For customers wanting security beyond standard residential locks, the high-security category is the answer. A locksmith should understand the major brands, their key features, and where each fits.
What "high-security" means
High-security locks differ from standard locks in:
- Key control: registered keys; can't be duplicated at hardware stores
- Anti-pick / anti-bump features: specific design countermeasures
- Drill resistance: hardened steel inserts
- Pull / kick resistance: reinforced strike + bolt
- Construction quality: heavier materials, tighter tolerances
- Certification: tested to specific security standards
Standard locks may have one or two of these; high-security combines all.
Standards and certifications
| Standard | What it covers |
|---|---|
| ANSI / BHMA A156.30 | High security cylinders |
| UL 437 | Burglary-resistant locks |
| ANSI Grade 1 | Heavy commercial / institutional |
| BHMA AHL | Door locks for commercial / residential |
UL 437 is the most common high-security designation in the US.
Major brands
Medeco
US-based; founded in the 1960s. Variants:
- Medeco 3: third-generation; current product line
- Medeco X4: latest; enhanced features
- Medeco Z: legacy
- M3: budget-friendly within Medeco line
Features:
- Angled pins (resist conventional picks)
- Sidebar mechanism (additional security layer)
- Restricted key blanks (key control)
- UL 437 listed
- Made in USA
Common applications: residential, light commercial, government.
Mul-T-Lock
Israeli company; popular in US commercial.
- Interactive+: standard high-security
- Hercular: heavy-duty
- MT5+: latest generation
- MT5+ patented key blank with sidebar + pins
Features:
- Telescopic pins (dimple keys)
- Active retainer pins
- Drill protection
- Key control
- UL 437 listed
Common applications: commercial, government, premium residential.
Abloy / Abloy Protec
Finnish company. Long-respected brand.
- Abloy Protec2: standard high-security
- Abloy Protec2 CLIQ: electronic version
- Abloy Disklock: traditional disk-detainer (oldest design)
Features:
- Disk-detainer mechanism (no pin tumblers)
- Anti-pick (different mechanism than standard)
- Extreme drill resistance
- Key control
- UL 437 listed
- Distinctive Finnish industrial design
Common applications: premium residential, government, high-security commercial.
ASSA
Swedish company. Owned by ASSA ABLOY conglomerate.
- Twin: dual-bitting key
- Twin Maximum Plus: enhanced
- 6000 Series: commercial
Features:
- Twin disk + pin design
- Side milling on the key
- Key control
- UL 437 listed
- European market dominant; growing in US
Kwikset SmartKey Security
Mass-market "high-security" tier:
- Patent-protected sidebar
- Pick-resistant per Kwikset claims
- Easy rekeying by homeowner
- Bump-key resistant
NOT UL 437 listed. Different tier than the brands above. Suitable for higher-security residential but not commercial / institutional.
Feature comparison
| Feature | Medeco 3 | Mul-T-Lock MT5+ | Abloy Protec2 |
|---|---|---|---|
| Pick resistance | Very high | Very high | Highest |
| Bump resistance | Very high | Very high | Excellent (no bump possible) |
| Drill resistance | High | High | Very high |
| Pull / kick resistance | Per door reinforcement | Per door reinforcement | Per door reinforcement |
| Key control | Restricted; geographic | Restricted; geographic | Restricted; geographic |
| Patent protection | Active (current generation) | Active (current generation) | Active (current generation) |
| Aesthetics | Standard cylinder appearance | Standard cylinder appearance | Distinctive (different than pin tumblers) |
| Servicing | Standard cylinder body | Standard cylinder body | Specialty equipment needed |
| Cost | High | High | Highest |
Each has strengths; choice depends on customer priorities.
Key control
The defining feature of high-security:
- Keys can NOT be duplicated at standard hardware stores
- Original purchase requires:
- Authorized dealer
- Card / ID showing authorization
- Documentation
- Duplication requires the same authorization
- Lost key replacement may require complete re-keying
This is the customer's most important reason to choose high-security.
Drill resistance
High-security locks resist drilling:
| Component | Resistance feature |
|---|---|
| Cylinder body | Hardened steel insert |
| Driver pins | Hardened |
| Side bar / pin set | Drill-resistant materials |
| Spring caps | Hardened |
Drilling is the most common attack on standard cylinders. High-security cylinders take 15-30+ minutes of drilling vs. <2 minutes for standard. The deterrent value matters.
Bump resistance
Bump-key attacks:
- A standard cylinder can be picked / bumped quickly with specialty keys
- High-security cylinders have features that defeat this
- Medeco: angled pins
- Mul-T-Lock: telescopic pins + sidebar
- Abloy: no pin tumblers at all
- ASSA: dual mechanism
Bump-resistance is a key feature of modern high-security.
When to specify high-security
| Customer profile | Recommendation |
|---|---|
| Standard residential home | Standard Grade 2 sufficient |
| High-value residential (jewelry, art, etc.) | High-security recommended |
| Vacation home (away periods) | High-security recommended |
| Commercial (cash, valuables, sensitive areas) | High-security required |
| Server rooms / IT spaces | High-security + key control |
| Government / institutional | High-security required |
| Pharmacy / medical | High-security required (regulatory in some cases) |
| Healthcare facilities | High-security per HIPAA / regulations |
For most residential customers, the additional cost is justified by the additional security.
Cost framework
The relative tier:
| Tier | Lock cost (relative) |
|---|---|
| Standard residential (Kwikset, Schlage non-high-security) | Baseline |
| Mid-tier Schlage Primus | 2-3x baseline |
| Medeco / Mul-T-Lock / ASSA | 3-5x baseline |
| Abloy Protec2 | 4-6x baseline |
| Premium installations (multiple locks + commercial) | Significantly higher |
Plus the installation cost. High-security is a meaningful investment.
Installation considerations
For high-security locks:
- Verify door + frame can accept the lock (size, hole patterns)
- Some require door reinforcement (strike plates, security strikes)
- Cylinder body fits standard door hardware (in most cases)
- Different door hardware required for some brands
Specifications vary by brand; verify before specifying.
Re-keying high-security locks
For existing high-security locks:
References
- UL 437 (Burglary-Resistant Cylinder Locks)
- ANSI / BHMA A156.30 (High Security Cylinders)
- Manufacturer documentation (Medeco, Mul-T-Lock, Abloy, ASSA)
- ALOA (Associated Locksmiths of America) training materials
- IDA (Institutional Drug Abuse) and pharmacy regulations (where applicable)
- Manuall internal: Lock Types Mechanisms, Master Key Systems, Smart Lock Options