High-Security Locks: Medeco vs. Mul-T-Lock vs. Schlage Primus

Most residential locks ship from the factory at price points designed to keep new home builders happy — not to keep determined burglars out. Standard Kwikset and Schlage residential lines, the kind that come with new construction, are roughly equivalent in security to the locks on a school locker. Useful, but not what you actually want on the front door of a family home.

Above that tier, three brands dominate the U.S. residential high-security market: Medeco, Mul-T-Lock, and Schlage Primus. All three are real high-security hardware. Choosing between them depends on your specific priorities.

What “high security” actually means

A residential high-security lock should defeat at least these four attack methods:

1. Lock picking — using picks and tension wrenches to manipulate pins individually
2. Bump keys — a specialty key tapped to bounce pins past the shear line (more on bump keys here)
3. Drilling — drilling out the cylinder face to defeat the pin stack
4. Forced entry — kicking, prying, or otherwise breaking the lock physically

It should also include key control — meaning duplicate keys can’t be cut at the local hardware store by anyone with $2 and your key in hand.

The three brands below all defeat these threats. They differ in how, and how well.

Medeco

The American high-security standard. Founded 1968, headquartered in Virginia, owned by Assa Abloy.

Defense mechanism: Pin design that requires both vertical alignment (standard pin-tumbler logic) AND rotational alignment (each pin must rotate to a specific angle). The rotation is controlled by an angled cut on the key. Bumping moves pins vertically but cannot rotate them. Picking is dramatically harder because you need to pick and rotate each pin.

Drill resistance: Hardened steel rollers and pins resist drilling.

Key control: Restricted keyway. Keys can only be cut by Medeco-authorized locksmiths with documented authorization from the registered key holder.

Best for: Homeowners who want the gold-standard U.S. brand, where dealer support and key reorder is well-established. Strong reputation with insurance carriers as “high-security” hardware.

Typical residential cost (installed): $350–$500 per lock for the Medeco Maxum line.

Mul-T-Lock

Israeli engineering, owned by Assa Abloy (same parent as Medeco). Founded 1973.

Defense mechanism: Pin-in-pin design — each “pin” is actually two concentric pins, an inner pin and a surrounding outer sleeve. Both must align at the shear line. Modern Mul-T-Lock cylinders (the MT5+ generation) add a second sidebar mechanism, making them effectively pick-proof for non-specialist attackers.

Drill resistance: Multiple hardened steel inserts and anti-drill pins.

Key control: Restricted keyway, even tighter key control than most Medeco implementations. Each key is registered to a specific authorized customer and can only be reordered with that customer’s documented authorization.

Best for: Homeowners who want the most pick- and bump-resistant hardware available, and who don’t mind that the keys feel slightly different in the hand (the cuts are dimples rather than traditional cuts). Strong choice for homes in higher-threat environments.

Typical residential cost (installed): $350–$500 per lock for MT5+.

Schlage Primus

Schlage’s high-security line, owned by Allegion (separate from the Medeco/Mul-T-Lock parent company). Has been on the market for decades.

Defense mechanism: Standard pin-tumbler cylinder PLUS a sidebar that requires the key to have specific milled “fingers” along the side. The sidebar pins must align and the side fingers must engage correctly. Bumping defeats the standard pins but cannot defeat the sidebar.

Drill resistance: Hardened pins and reinforced cylinder housing.

Key control: Restricted keyway with dealer registration. Slightly less strict key control than Medeco or Mul-T-Lock in practice, depending on which Primus level you choose (Standard, XP, Everest).

Best for: Homeowners who want high-security upgrade hardware that works with existing Schlage Grade 1 deadbolts (good if you already have Schlage hardware and want to upgrade just the cylinder). Generally the most affordable of the three.

Typical residential cost (installed): $250–$400 per lock for Primus XP.

Side-by-side comparison

Feature	Medeco	Mul-T-Lock MT5+	Schlage Primus
Bump resistance	Excellent	Excellent	Excellent
Pick resistance	Excellent	Best in class	Very good
Drill resistance	Excellent	Excellent	Very good
Key control	Excellent	Best in class	Very good
Aftermarket key availability	Wide (Assa Abloy network)	More restricted	Wide (Schlage network)
Insurance recognition	Strong	Strong	Strong
Typical installed cost per lock	$350–$500	$350–$500	$250–$400
Key feel	Traditional cut + side angle	Dimple key	Traditional cut + side fingers

Which one is right for you?

Most of our residential customers end up with Schlage Primus as the budget choice or Medeco Maxum as the premium choice — Mul-T-Lock is the right answer for specific situations (very high threat environment, existing Mul-T-Lock infrastructure, or specific commercial cross-keying needs).

Choose Medeco if:

• You want the most well-recognized U.S. high-security brand
• Your insurance carrier specifically recognizes Medeco for premium discounts
• You value the dealer network and long-term key support

Choose Mul-T-Lock if:

• Maximum pick / bump resistance is your top priority
• You’re comfortable with dimple-key feel
• You’re keying multiple homes / properties with the strictest possible key control

Choose Schlage Primus if:

• You already have Schlage Grade 1 deadbolt hardware and want to upgrade just the cylinder
• Budget matters and you want real high-security at the lowest premium tier
• You want the widest aftermarket key support

What we recommend by use case

Single-family home, average threat environment → Schlage Primus front and back, standard hardware on side / garage doors. Total install: $500–$800.

Single-family home, high-value contents or specific concerns → Medeco Maxum or Mul-T-Lock MT5+ on every exterior door. Total install: $1,200–$2,000.

Multifamily / commercial property → Mul-T-Lock or Medeco with master key system integration. Site walkthrough required for accurate quote.

After a break-in attempt → Whatever you upgrade to, also reinforce the strike plate (3-inch+ screws into the framing) and consider a full lock change rather than just rekey.

Where we install

We install Medeco, Mul-T-Lock, and Schlage Primus across the Delaware Valley (Philadelphia, South Jersey, Wilmington DE) and Houston, TX. Schedule a quote through our residential service, see our pricing, or call the main line.

We don’t push the most expensive option by default. We’ll ask about your home, your concerns, your budget, and recommend the lock that actually fits — including telling you when standard Grade 1 hardware is enough for your situation.

Family-owned, multi-state licensed, BBB A+ accredited since 2007.