High-Security Lock Installation NYC — Medeco & Mul-T-Lock
A high-security lock buys you two things a standard lock cannot: keys that cannot be copied behind your back, and a cylinder built to shrug off attack attempts. This spring we installed a complete Mul-T-Lock system for an apartment client and upgraded the locks on a luxury residence with custom oversized doors — both jobs photographed on our recent jobs page. Sunny Locksmith installs Medeco M4 and Mul-T-Lock MT5+ hardware across NYC under License #2096389-DCA. Call (917) 495-1990.
What "High-Security" Actually Means
Marketing has worn the phrase out, so here is the working definition we use: a high-security lock has a restricted keyway, so blank keys are not sold to the public and copies require your authorization card at a licensed dealer; and it has a UL 437 rated cylinder, so attacking it takes tools and time a burglar does not have. Medeco M4 and Mul-T-Lock MT5+ meet both tests. A bargain "heavy duty" deadbolt from the hardware store meets neither.
Key Control Is the Real Product
Most break-ins into NYC apartments do not involve any fancy technique — they involve a key that should not exist. A former roommate, an ex, a contractor, a previous tenant. With a restricted keyway, every key in circulation is one you personally authorized. That is what the Mul-T-Lock installation we did this spring bought the client: not just a stronger cylinder, but a complete accounting of who can open the door.
Medeco M4 vs. Mul-T-Lock MT5+
We install both weekly, and the honest difference is small. Medeco M4 pins rotate as well as lift, and it holds up famously against drilling. Mul-T-Lock MT5+ uses telescoping pin-in-pin technology plus a slider element. Both have restricted keyways. Our advice usually comes down to the door: what fits the existing prep, what the building keyway situation is, and which dealer network is more convenient for your future key copies.
Installation on Real New York Doors
Pre-War and Mortise Doors
You do not need to replace a beautiful pre-war mortise lock to get high security. We fit MT5+ and Medeco cylinders into existing mortise bodies — the door keeps its hundred-year-old face, the lock gets a modern brain. We do this on Upper West Side and Brooklyn Heights doors constantly; recent mortise work from 72nd St & Broadway and Sunset Park is on our work page.
Luxury and Custom Doors
The luxury apartment upgrade we did this spring involved custom oversized doors — the kind where standard backsets and strike plates simply do not fit. We source extended backset latches and custom strikes, and we match finishes (oil-rubbed bronze, satin nickel, polished brass) so the security upgrade does not fight the interior design.
The Frame Matters as Much as the Cylinder
A pick-proof cylinder on a kickable frame is security theater. Every high-security install we do includes a look at the strike side: heavy-duty strike plate, 3-inch screws into the stud, and on vulnerable doors a latch guard so the bolt cannot be attacked with a bar. If the door itself is the weak point, we say so before you spend money on the cylinder.
Who Actually Needs This
Honest answer: not everyone. If you are worried about a specific person with a key — get a restricted keyway, it is built for exactly that. If your building has had break-ins through the door, get the UL 437 cylinder plus frame reinforcement. If your threat model is a lost key once a decade, a quality Grade 1 deadbolt and a rekey will serve you fine, and we will tell you so. Businesses with staff turnover should look at restricted-keyway systems across all doors — see commercial high-security locks.
Service Areas — High Security Lock Installation NYC
Frequently Asked Questions
Can you put a high-security cylinder in my existing lock?
Very often, yes. Medeco and Mul-T-Lock make cylinders in mortise, rim, and standard key-in-knob formats, so we can usually upgrade the cylinder and keep your existing hardware — including pre-war mortise bodies, which keep their original look.
Can someone copy a Medeco or Mul-T-Lock key at a hardware store?
No. The keyways are restricted: blanks are not sold to the public, and copies require your authorization card at a licensed dealer. That is the main reason to buy these locks — every key in circulation is one you approved.
Are high-security locks worth it for a rental apartment?
If you are worried about who holds copies of your key — a previous tenant, an ex, building staff — yes, and a restricted keyway solves exactly that. Check your lease first; we regularly coordinate with landlords and supers so the install does not violate building rules.
Whats the difference between this and a regular Grade 1 deadbolt?
A Grade 1 deadbolt resists force well but its keys can be copied anywhere and its cylinder can be picked or drilled with common tools. High-security cylinders add restricted key control and UL 437 attack resistance. Many of our installs combine both: Grade 1 hardware with a Medeco or Mul-T-Lock cylinder inside.
Available 24/7 across NYC. NYC License #2096389-DCA.
