Treasure Coast Locksmith provides high-security locks services in Port St. Lucie, Stuart, Fort Pierce, Vero Beach, Jensen Beach, and across the Treasure Coast. Call (772) 758-1322 for mobile service. High-security locks (Medeco M3, Mul-T-Lock MT5+, Schlage Primus) combine pick resistance, bump resistance, and restricted keyways that cannot be duplicated at a hardware store. Installed on coastal Treasure Coast homes that need maximum protection. $345-$595 per lock installed.
A standard Grade 1 Schlage deadbolt is excellent hardware. It is also pickable by anyone who has practiced for an afternoon on YouTube, and its key can be copied at any hardware store with a $3 blank. For most homes that tradeoff is fine.
For homes with valuables, a history of key loss, or owners who travel frequently, it is not.
High-security locks solve both problems. The cylinder is engineered with patented side-bar mechanisms and interactive elements that defeat picking and bumping. The key is a restricted profile that cannot be duplicated without a legal authorization and specialty equipment.
Medeco, Mul-T-Lock, and Schlage Primus are the three brands that dominate this category.
Treasure Coast Locksmith is an authorized dealer for all three. We install, rekey, and duplicate keys for high-security systems across every city in the tri-county area.
What high-security locks give you
- Pick resistance - patented side bars and sliders defeat standard picks.
- Bump resistance - spool and serrated pin stacks prevent bump key attacks.
- Restricted keyways - no hardware-store duplication, ever.
- Legal key control - duplication requires signed authorization.
- Drill resistance - hardened inserts in the cylinder body.
- Key tracking - manufacturer logs every key cut in the system.
- 25-year mechanical life - build quality exceeds standard Grade 1.
- Coastal finishes available - Medeco in brass and Mul-T-Lock in satin chrome PVD.
Who needs high-security locks
High-security is not for every home. These are the situations where it makes genuine sense.
When to upgrade to high-security
- Home on Jupiter Island with valuable art collection. Standard locks are a known weakness. Medeco M3 throughout.
- Homeowner has lost keys multiple times over the years. Restricted keyway prevents anyone from copying lost keys.
- Stuart home with a history of attempted break-ins. Upgrade to Mul-T-Lock MT5+ with drill-resistant hardened inserts.
- Snowbird home in Vero Beach left empty 6 months a year. High-security locks resist opportunistic attacks.
- Port St. Lucie medical professional with controlled substances at home. Schlage Primus for legal compliance.
- Homeowner with a household employee they want to give limited access. Restricted keyway prevents employee from making copies.
- Hutchinson Island beachfront home concerned about casual break-in attempts. Full Mul-T-Lock retrofit.
- Home office with business records and equipment. Medeco Maxum on the office door and home entry.
Medeco vs Mul-T-Lock vs Schlage Primus
Three brands dominate the residential high-security market. Each has a different mechanical approach and different strengths.
Medeco M3 uses a rotating pin tumbler system. Each pin can rotate independently and must be at the correct angle as well as the correct height to align the shear line. This defeats standard pick attacks because you cannot feel the rotation during picking.
Medeco also uses a side-bar that engages slots in the pins, adding a second check. The M3 key profile is patented and restricted, meaning only authorized Medeco dealers can cut replacement keys. Mechanical life is 25+ years.
Price is the lowest of the three high-security options.
Mul-T-Lock MT5+ uses a telescopic pin system and a "dimple" keyway. The key has dimples pressed into both sides of the blade, and internal telescopic pins must align in three dimensions simultaneously. No known field-level non-destructive attack exists on MT5+.
The key profile is the most restricted of the three - duplication requires signed owner authorization sent to the factory in some cases. Mechanical life is 25+ years. Price is the highest.
Schlage Primus uses a side-bar design with interactive sliders. It is compatible with standard Schlage hardware bodies, so a Primus cylinder drops into an existing Schlage B-series deadbolt. This makes Primus the easiest upgrade path for homeowners who already have Schlage hardware and want to upgrade just the cylinder.
The keyway is restricted but not as tightly as Medeco or Mul-T-Lock. Mechanical life is 25+ years. Price is in the middle.
Which one to pick depends on your existing hardware, your threat model, and your willingness to deal with restricted-key paperwork. For most Treasure Coast homes we recommend Medeco M3 for best overall value. Homes with the highest protection requirements get Mul-T-Lock MT5+.
Homes already running Schlage who want a simple cylinder-only upgrade get Primus.
How a high-security install works
Phone call and consultation
Call (772) 758-1322. We discuss your threat model and recommend the right brand.
Authorization paperwork
Restricted keyway systems require owner signature on authorization paperwork for legal key control.
Onsite installation
Mobile installation with matched keying across all exterior doors. Typical time is 60-120 minutes.
Key provisioning
You receive the original keys and authorization documents for future duplication requests.
High-security ownership tips
- Keep the authorization paperwork in a safe place. You need it to get replacement keys cut in the future.
- Label your high-security keys so you know which door each key opens - the keys look similar and are hard to tell apart.
- If you lose a high-security key, rekey rather than just cutting a replacement. You never know who has the lost key.
- Change the keying hierarchy every 5-7 years for ongoing security, even without incidents.
- Store a spare high-security key in a safe, not on a hide-a-key outside. The restricted keyway is only effective if the key stays controlled.
- For household employees, issue a restricted key that operates only the doors they need access to. This uses the master keying feature.
Related services
Other Treasure Coast Locksmith services in this cluster.
High-security lock FAQs
The questions Treasure Coast homeowners ask about upgrading to Medeco, Mul-T-Lock, or Schlage Primus.
How much does a high-security lock cost?
Medeco Maxum deadbolt runs $345 to $445 installed. Mul-T-Lock Hercular runs $395 to $545 installed. Schlage Primus cylinder retrofit into existing Schlage hardware runs $225 to $325.
Full-house high-security upgrade (4-6 doors) typically runs $1,500 to $3,200 including hardware, installation, and restricted key paperwork.
Are high-security locks really worth it?
For homes with valuables, frequent travel, or history of key loss - yes. For a standard 3-bedroom Treasure Coast home with low crime exposure, standard Grade 1 Schlage is usually sufficient. The upgrade makes most sense when you specifically want pick resistance, bump resistance, or restricted key control that standard Grade 1 cannot provide.
What is a restricted keyway?
A restricted keyway is a key profile that is legally and mechanically protected from unauthorized duplication. The manufacturer only sells the key blanks to authorized dealers, and dealers require signed authorization from the registered owner before cutting a new key. This prevents anyone with a lost key from copying it at a hardware store.
Can Medeco locks be picked?
In a laboratory setting with specialty tools and hours of work, yes - all mechanical locks can eventually be picked. In the real world, Medeco M3 has no known field-level non-destructive attack. A burglar would have to be trained for weeks and carrying specialty tools to defeat it, which does not describe typical residential burglars.
For practical purposes, Medeco is pick-proof.
How do I get a replacement Medeco key?
Call us with your authorization paperwork. We verify you are the registered owner, cut the replacement key with our Medeco-authorized equipment, and log the duplication in the key tracking system. New Medeco keys run $35 to $55 each depending on complexity.
Do high-security locks need special maintenance?
No. Standard pin-tumbler-safe lubricant twice a year is all they need. Medeco and Mul-T-Lock are actually more tolerant of salt air and humidity than standard Schlage and Kwikset because they use tighter tolerances and better materials.
Can I use my existing doors with high-security locks?
Almost always. Medeco, Mul-T-Lock, and Schlage Primus all use standard 2-1/8 inch residential cross-bore dimensions. They fit existing door prep.
Schlage Primus specifically drops into existing Schlage B-series bodies with zero door modification - just cylinder swap.
What is the difference between Grade 1 and high-security?
Grade 1 is the ANSI/BHMA mechanical grade (durability and security testing). High-security is an additional category that adds pick resistance, bump resistance, and restricted keyway protection. A lock can be Grade 1 without being high-security.
A high-security lock is almost always also Grade 1.
Can I master-key my high-security system?
Yes. Master keying is actually one of the strengths of Medeco and Mul-T-Lock. Both support multi-level master key hierarchies with full mechanical and legal control.
We can design a master system for a single home, a vacation property cluster, or a small business owned by the homeowner.
Do high-security locks work with smart locks?
Yes, partially. You can install a Medeco or Mul-T-Lock cylinder in a mechanical deadbolt with Bluetooth smart controls (like some August retrofit options). Full smart locks with integrated cylinders (Schlage Encode, Yale Assure, Kwikset Halo) do not yet support true high-security keyways.
If you want both, use a traditional high-security deadbolt plus a separate smart lock on another door.
Are high-security locks drill-resistant?
Yes. All three brands use hardened inserts in the cylinder body at key locations. A drill attempt against a Medeco, Mul-T-Lock, or Primus cylinder is measurably harder than against a standard deadbolt - typically 4-5 minutes versus 30-45 seconds for a standard deadbolt.
For physical attacks, this is meaningful.
How long do high-security locks last?
Mechanical life is 25+ years for all three brands in non-coastal use. Coastal exposure cuts this to 15-20 years but still significantly longer than standard hardware. The keys themselves are more durable than standard keys because of the heavier alloy and precision machining.