Treasure Coast Locksmith provides Mul-T-Lock installation services in Port St. Lucie, Stuart, Fort Pierce, Vero Beach, Jensen Beach, and across the Treasure Coast. Call (772) 758-1322 for mobile service. Mul-T-Lock Hercular MT5+ is the highest-security residential lock commercially available. It uses a patented dimple keyway with telescopic pins requiring 3D alignment. No known field-level non-destructive attack exists.
More expensive than Medeco but maximum security for homes that need it.
Mul-T-Lock Hercular MT5+ is the most pick-resistant residential lock commercially available. If Medeco M3 represents very high security, Mul-T-Lock MT5+ represents maximum security. The dimple keyway with telescopic pin system is mechanically more complex than any other residential cylinder and has no known field-level non-destructive attack.
The tradeoff for maximum security is cost. Mul-T-Lock hardware runs 15-25% more than Medeco. Mul-T-Lock keys are harder to duplicate (even with authorization) because the dimple cuts require specialty factory equipment.
For most Treasure Coast homes, Medeco is sufficient. For the homes that truly need the highest security tier - beachfront with valuables, celebrity residences, business owners storing cash or records - Mul-T-Lock is the answer.
Treasure Coast Locksmith is an authorized Mul-T-Lock dealer for the Hercular MT5+ residential line.
What Mul-T-Lock MT5+ gives you
- Patented dimple keyway - 3D cut pattern unique to Mul-T-Lock.
- Telescopic pin tumblers - pins move in 3 dimensions.
- No known field attacks - maximum commercially available security.
- Restricted key control - most restrictive of any residential brand.
- Drill and pry resistance - hardened inserts throughout cylinder body.
- 25+ year mechanical life - built to commercial standards.
- Coastal-appropriate finishes - satin chrome PVD and brass.
- Matches Medeco on bump and pick - with additional dimple complexity.
When Mul-T-Lock is the right call
Mul-T-Lock is for the situations where Medeco's 'near-perfect' is not good enough.
Maximum security scenarios
- Oceanfront Jupiter Island home with high-value art collection - owner specifically asked for the highest available residential security.
- Beachfront home on Hutchinson Island where owner had a previous break-in and wants maximum deterrent.
- Business owner in Stuart storing business records and cash at home. MT5+ on all entries.
- Vero Beach snowbird home left empty 6 months a year. Mul-T-Lock as insurance against opportunistic attacks.
- Retired professional with high-net-worth profile wanting anonymity and maximum security.
- Client with specific threat concerns (celebrity, domestic dispute, business dispute). Mul-T-Lock as part of comprehensive security.
- Rental property in high-crime area where the owner is absent and wants the strongest possible tenant-protective hardware.
- Gun safe room door in a Tradition home requiring the highest-level access control.
How Mul-T-Lock MT5+ security works
Mul-T-Lock's key innovation is the telescopic pin system. In a standard lock, pin tumblers move only up and down. In Mul-T-Lock, each pin is actually two pieces that move in 3 dimensions: the pin moves up and down for height, and the inner telescoping core extends or retracts independently.
Each key dimple has both a depth and an orientation that controls the telescopic state.
The result is that every pin position has two independent variables that must be correct. For a 5-pin lock with 10 possible heights and 8 possible telescopic states, the total key space is 80^5 = 3.3 billion possible keys. Compared to a standard Schlage with about 10^5 = 100,000 possible keys, Mul-T-Lock is mechanically 33,000x more complex.
From a picking perspective, this complexity makes the lock essentially unpickable. You cannot feel the telescopic state with a pick - it requires the physical dimple of a correct key to set. Bump attacks fail for the same reason: no bump key can produce the 3D alignment needed.
The restricted keyway is equally important. Mul-T-Lock keys cannot be reproduced even by other authorized dealers without the factory key card that was issued when the lock was installed. You have to have the original paperwork, and the paperwork is tied to a specific lock serial number.
This makes unauthorized key duplication functionally impossible, even from a lost key.
How Mul-T-Lock installation works
Phone call and threat assessment
Call (772) 758-1322. We discuss your security requirements and whether MT5+ is the right fit.
Authorization paperwork
Full registration paperwork required for restricted keyway control.
Onsite installation
Hardware installed with matched keying across all exterior doors.
Key card documentation
Owner receives Mul-T-Lock key card required for any future key work.
Mul-T-Lock ownership tips
- Guard your Mul-T-Lock key card paperwork like a car title. You cannot get replacement keys without it.
- Keep a spare MT5+ key in a bank safe deposit box - never a hide-a-key or magnetic box.
- Mul-T-Lock keys are tougher than standard but still break under extreme force. Don't use one as a screwdriver.
- If you lose the key card, contact us immediately to begin the factory reauthorization process (it's slow).
- Change your keying every 5-7 years for ongoing security.
- Document your installation with photos and serial numbers for insurance and any future work.
Related services
Other Treasure Coast Locksmith services in this cluster.
Mul-T-Lock installation FAQs
Common questions about Mul-T-Lock residential installation.
How much does Mul-T-Lock installation cost?
Single Mul-T-Lock Hercular MT5+ deadbolt installation runs $395 to $545. Full-house upgrade (4-6 doors) runs $1,750 to $2,950. MT5+ replacement keys run $45 to $75 each.
The brand runs 15-25% higher than Medeco because of the more restrictive key control and more complex mechanism.
Is Mul-T-Lock better than Medeco?
Marginally, at the top end. Both Medeco M3 and Mul-T-Lock MT5+ are excellent high-security locks with no known field-level non-destructive attacks. Mul-T-Lock has slightly more restrictive key control and a more complex mechanism.
For most Treasure Coast homes the difference is negligible and Medeco wins on value. For maximum security only, Mul-T-Lock wins.
Can Mul-T-Lock keys be duplicated?
Only by authorized Mul-T-Lock dealers with the factory key card from the original installation. This makes Mul-T-Lock the most restrictive residential keyway available. Even losing the original key does not allow anyone to duplicate it without the paperwork.
What if I lose my Mul-T-Lock key card?
Contact us immediately. We can initiate a factory re-registration process to reauthorize duplication, but it requires proof of ownership and takes 2-4 weeks. This is why we strongly recommend keeping the key card in a secure location like a bank safe deposit box.
Can Mul-T-Lock be installed on my existing door?
Yes. MT5+ uses the standard 2-1/8 inch residential cross-bore. It drops into any door currently set up for a standard deadbolt.
No door modification needed. Installation is straightforward.
How long do Mul-T-Lock locks last?
Mechanical life is 25+ years under normal residential use. The tight manufacturing tolerances and premium materials actually make Mul-T-Lock more durable than average. Coastal exposure cuts this to 18-22 years but still significantly longer than standard hardware.
Is Mul-T-Lock worth the extra cost over Medeco?
For most homes, no. Medeco M3 provides effectively the same pick and bump resistance at 15-25% lower cost. The extra Mul-T-Lock cost buys more restrictive key control and a more complex mechanism, which matters for truly high-threat situations but is overkill for typical residential security.
Can Mul-T-Lock be rekeyed?
Yes. MT5+ cylinders can be rekeyed by an authorized dealer with the factory pin kits and the owner's key card paperwork. Rekey runs $95 to $155 per cylinder - higher than Medeco because of the more complex pin system.
Does Mul-T-Lock come in coastal finishes?
Yes. Satin Brass, Polished Brass, and Satin Chrome PVD are available. Solid brass construction gives Mul-T-Lock natural corrosion resistance beyond what the finish provides.
Good choice for oceanfront homes that need both security and coastal durability.
Is Mul-T-Lock HOA-approved?
Yes at most Treasure Coast HOAs that accept high-security hardware. Mul-T-Lock in satin or polished brass matches common association finish requirements. We verify HOA approval before installation.
Can Mul-T-Lock be master keyed?
Yes. Mul-T-Lock supports multi-level master keying for residential and light commercial applications. A single master can open all doors while individual keys open only specific doors.
Very useful for households with household employees or multi-tenant rental properties.
How fast can you install Mul-T-Lock?
For scheduled installs, usually within a week because we order the hardware from the factory with the owner's registration paperwork. For stocked Mul-T-Lock in common finishes, installation can be same-day to next-day. Full-house installs take 3-4 hours onsite.