Locksmith Mul-T-Lock

Mul-T-Lock: Israeli engineering for maximum pick resistance

Mul-T-Lock is an Israeli manufacturer founded in 1973, now part of the Assa Abloy group. The brand built its reputation on a single innovation: the pin-in-pin system, where each driver pin contains a smaller internal pin that must align independently. This doubles the number of shear lines the cylinder presents to an attacker, making Mul-T-Lock one of the most pick-resistant mechanical lock systems available in Belgium.

Interactive+ versus MT5+: which level of protection do you need?

The Interactive+ is the model we install most frequently. It uses the telescopic pin-in-pin mechanism combined with a floating element in the key that interacts with a corresponding element in the cylinder. This makes key duplication extremely difficult without the proprietary card. The cylinder holds up well against bumping, picking, and drilling.

The MT5+ takes things further. It adds a sidebar mechanism on top of the pin-in-pin system, creating a dual-locking principle. The key profile is also more complex, with additional milling on the blade side. In independent testing, MT5+ cylinders have resisted manipulation for over 30 minutes, which exceeds the highest European security ratings. We recommend the MT5+ for standalone villas, ground-floor offices, and any property where the door is the primary security layer.

Where we see Mul-T-Lock in Brussels

Mul-T-Lock has a strong presence in the Brussels villa market, particularly in Uccle, Watermael-Boitsfort, and the Woluwe communes. Homeowners who invest in individual houses tend to choose higher-security cylinders, and Mul-T-Lock sits at the top of that range. We also install them regularly in professional settings: law offices, medical practices, and small businesses where sensitive documents or equipment need protection.

We fit around 8 to 12 Mul-T-Lock cylinders per month. It is not our highest-volume brand, but the interventions tend to be more involved, as clients choosing Mul-T-Lock often want a full security assessment rather than a simple cylinder swap.

Key duplication and the ownership card

Like other high-security brands, Mul-T-Lock uses a card-based key protection system. The ownership card is required for every key copy. What sets Mul-T-Lock apart is the card's digital registration: each card is tied to a specific cylinder serial number in a central database. Even if someone finds your card, they cannot order keys without knowing the registered owner's details.

If the card is lost, replacement involves contacting Mul-T-Lock's authorised network with proof of property ownership. We handle this process regularly and it typically takes 10 to 15 working days.

Maintenance and longevity

Mul-T-Lock cylinders are built to last. The pin-in-pin mechanism is robust, and we rarely see wear-related failures before 12 to 15 years of use. The main maintenance requirement is periodic lubrication with a graphite or PTFE-based spray. We advise against oil-based lubricants, which attract dust and can gum up the telescopic pins over time.

If you are considering Mul-T-Lock for your property, we can assess your current setup and advise on the right model. Not every door needs an MT5+, and we will tell you honestly when an Interactive+ is enough.