Medeco vs Mul-T-Lock vs ASSA: High-Security Locks in NYC

A standard deadbolt stops an opportunist. A high-security cylinder stops a professional. The difference lives in three things: whether the lock can be picked, whether it can be drilled, and whether someone can walk into a hardware store and copy your key. For NYC residents and businesses who actually need that level, three names cover most of the market: Medeco, Mul-T-Lock, and ASSA. They are not interchangeable. Here is how they differ and which belongs on your door.

Note up front: this is about cylinders, the part that accepts the key, not the deadbolt body. We compared the residential deadbolt brands (Schlage, Kwikset, Mul-T-Lock) in our deadbolt comparison. This post is the high-security tier, the cylinders we install when the threat model is real.

What "high security" actually means

The term is marketing unless it is backed by a standard. The one that matters for cylinders is UL 437 (forced-entry and pick resistance), often paired with ANSI/BHMA A156.30 for high-security cylinders. A genuine high-security cylinder delivers three things at once:

• Pick and bump resistance beyond a standard pin-tumbler, through extra security pins, sidebars, or alternative mechanisms.
• Drill resistance, via hardened steel inserts and ball bearings in the cylinder body.
• Key control, meaning the key blank is patented and restricted, so duplicates can only be cut by authorized dealers against a signature card. This is the feature most people underrate and most need.

A lock can be pick-resistant and still be a security hole if anyone can copy the key. Key control closes that gap.

Medeco

Medeco built its name on the angled-cut key: the pins must be both lifted to the right height and rotated to the correct angle, and a sidebar checks the rotation. That dual requirement makes traditional picking very hard.

• Strengths: excellent pick resistance, hardened anti-drill construction, strong patent-protected key control (Medeco3 and similar). Made in the USA, widely serviced. The angled-cut design is genuinely difficult to defeat non-destructively.
• Trade-offs: premium price; key duplication is restricted to authorized dealers (a feature, but it means you plan ahead for spares).
• Best for: residential front doors where pick resistance is the priority, ground-floor and brownstone units, clients who have been targeted, and anyone who wants strong key control with US-made hardware.

Mul-T-Lock

Mul-T-Lock uses a telescoping pin-within-a-pin system (the classic interactive design) and, in the MT5+ line, an alpha-spring and additional ball-bearing element. It is the cylinder we reach for often in NYC because it fits a wide range of bodies and offers extremely strong key control.

• Strengths: very strong pick and bump resistance, hardened anti-drill inserts, excellent restricted key control with signature-card duplication, and broad compatibility (deadbolt cylinders, rim cylinders, mortise cylinders, padlocks). The MT5+ keyway is hard to source and copy.
• Trade-offs: premium price; restricted keys cost more to duplicate than hardware-store keys (by design).
• Best for: apartments and brownstone vestibules where you want one high-security key across multiple cylinders, commercial doors, and key-control situations like offices where former staff must be locked out cleanly. Fits pre-war mortise cases well.

ASSA

ASSA (part of the same group as ASSA ABLOY) is a Scandinavian high-security line strong on key control and durability, common in commercial and institutional settings.

• Strengths: strong pick and drill resistance, excellent patent-backed key control, and a reputation for heavy-duty longevity. Strong fit for commercial master-key systems.
• Trade-offs: dealer network for service and duplication is thinner in some NYC neighborhoods than Medeco or Mul-T-Lock; premium price.
• Best for: commercial buildings, offices, and any setting being built into a master-key system where long-term key control and durability matter most.

Side-by-side

Feature	Medeco	Mul-T-Lock	ASSA
Pick resistance	Very high (angled cut + sidebar)	Very high (pin-in-pin + sidebar)	Very high
Drill resistance	Hardened inserts	Hardened inserts + ball bearings	Hardened, heavy-duty
Key control	Patent-restricted, US-made	Patent-restricted (MT5+)	Patent-restricted
Body compatibility	Wide	Very wide (mortise, rim, deadbolt, padlock)	Wide, strong in commercial
Best home for it	Residential pick resistance	Multi-cylinder + commercial	Commercial / master-key
Approx. installed cost (NYC)	$200-$450 per cylinder	$200-$450 per cylinder	$220-$480 per cylinder

All three are a large step up from a standard cylinder. The differences between them are smaller than the difference between any of them and the builder-grade lock most doors ship with.

Which one for your door

• A NYC apartment front door, pick and copy resistance the goal: Medeco or Mul-T-Lock. Either is excellent. Pick Mul-T-Lock if you want one key across several cylinders.
• A brownstone with a vestibule and a parlor door: Mul-T-Lock, keyed alike across both, with the original mortise case preserved.
• An office or commercial space with staff turnover: ASSA or Mul-T-Lock built into a master-key plan, so you can revoke and re-issue cleanly.
• You mainly want nobody copying your key: any of the three; all offer signature-card key control. This alone is worth the upgrade for many clients.

A reminder we make often: the strongest cylinder on a door with stock 3/4-inch strike screws still loses to a kick. Pair the cylinder with a reinforced strike and a Grade 1 deadbolt body. We explain why the strike matters more than people think in our cheap-deadbolt breakdown.

How we install and support it

1. We assess the door and what you are protecting against (picking, drilling, key copying, or all three), and recommend the cylinder that fits.
2. We confirm the cylinder fits your deadbolt or mortise body; often we swap just the cylinder and keep the existing hardware.
3. We install, register your signature card for restricted key duplication, and cut your authorized keys.
4. We can key multiple cylinders alike so one key runs your whole door set.

We are DCWP licensed and insured. See high-security locks, lock rekeying, and lock installation and repair. Call (844) 912-1908 for a straight recommendation; we will tell you when you do not need this tier, too.

Frequently Asked Questions

Do I really need a high-security lock for a NYC apartment? Most apartments do fine with a Grade 1 deadbolt and a reinforced strike. High-security cylinders are worth it for ground-floor units, brownstones, anyone previously targeted, and anyone who specifically wants nobody able to copy their key.

Can someone copy my Medeco or Mul-T-Lock key at a hardware store? No. The blanks are patented and restricted. Duplicates are cut only by authorized dealers against the signature card you receive at install. That is the key-control feature you are paying for.

Can I put a high-security cylinder in my existing deadbolt? Often yes. If the deadbolt body is sound, we swap only the cylinder, which is far cheaper than a full new lock and gets you the pick, drill, and key-control benefits.

Which is hardest to pick? All three are highly pick-resistant and beyond the skill of opportunistic attackers. Medeco's angled-cut and Mul-T-Lock's pin-in-pin designs are both excellent; for the average threat the practical difference is small.

Are these locks drill-proof? Drill-resistant, not drill-proof. Hardened inserts and ball bearings make drilling slow and difficult, which combined with pick resistance pushes most attackers to give up or move to forcing the door, where the strike plate becomes the deciding factor.

Will key duplication be a hassle? You plan ahead. Restricted keys cannot be copied on a whim, which is the point. We register your card at install and cut spares on request; many clients get a couple of extras up front.