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:
The lineage, which matters because the names get sold as if they were tiers:
- Biaxial: the older generation, still in the field in quantity
- Medeco3, also written M3: the generation after Biaxial. This is ONE product with two ways of writing it, not a premium line and a budget line. Anyone quoting you M3 as a cheaper alternative to Medeco3 does not know the platform
- X4: the current generation
Verify any other designation against current Medeco literature before you quote it; the catalog has been renamed more than once and retired names circulate on parts sites.
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 where the facility's own risk analysis calls for it. Do not tell a customer HIPAA specifies a lock. The Security Rule requires facility access controls as a physical safeguard and names no hardware grade, keyway, or certification; the spec comes out of their risk analysis, and controlled substances on site are governed separately by 21 CFR 1301.72 |
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:
- Identify the system first. Brand, keyway, and whether the keyway is a restricted or a patented profile. The bitting card or the original system paperwork tells you which dealer owns the system and what the key control terms are.
- Confirm who is authorized. Restricted and patented systems are re-keyed and cut only by the authorized dealer for that territory, against a signature card on file. If the system belongs to another dealer, the customer's path is that dealer, not you. Say so plainly instead of trying to work around it.
- Order blanks and pins through the channel. You cannot pick these up from the usual supply house. Lead time on restricted blanks is real, so quote the customer a date, not a same-day.
- Expect brand-specific pinning. Angled and rotating pins, sidebar elements, telescoping or dimple pins, and second-element components all mean the re-key is not a standard pin-tumbler job. Use the manufacturer's chart and the correct tooling; improvising here destroys expensive cylinders.
- Keep the system records straight. Update the bitting record, the key issue log, and the signature card as part of the job. The audit trail is most of what the customer paid for when they bought the system.
- Collect and account for the old keys. A high-security re-key that leaves keys unaccounted for gives back the exact control the customer is paying to keep.
- When re-keying is not worth it: an obsolete or discontinued platform with no blank supply, a cylinder with worn or damaged sidebar components, or a customer who has lost the authorization paperwork and cannot re-establish it. In those cases price a new system rather than nursing the old one, and tell the customer why.
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
- DEA controlled-substance security requirements, 21 CFR 1301.72, and state pharmacy board rules (where applicable)
- Manuall internal: Lock Types Mechanisms, Master Key Systems, Smart Lock Options