Medeco 4


Medeco builds on more than 50 years of lock engineering innovation and takes security to the next level, offering the highest level of protection against physical attack and unauthorized key duplication with Medeco 4 (M4).

M4 high security cylinders are UL 437 Listed with solid brass construction and hardened-steel inserts to thwart drilling attacks. In addition to bottom pins that lift and rotate, M4’s design includes 4 Side Pins made up of 3 Finger Pins and 1 Lift Pin. The Lift Pin is activated by contact with the Shuttle Pin movable element in the key, providing high-level key duplication integrity. The Finger Pins work with Secondary Side cuts on the key to provide increased security and greater potential combinations.

The patent-pending M4 key with Shuttle Pin movable element protects against the emerging threat of 3D printing for added credential security. Passing UL 437 and ANSI/BHMA rigid testing procedures affirms Medeco 4's ability to protect people and property.  


Medeco 4 Exploded View

Medeco 4 BiLevel

The Medeco 4 (M4) key system enables facilities to have a combination of high-security cylinders and cost-efficient cylinders all on the same key system, which is the perfect solution for managing key control. It provides patented key control and two levels of protection to ensure the right level of security for each opening in your facility.

M4 High Security cylinders are UL 437 listed, giving protection against physical attacks such as picking, drilling, and bumping.

M4 BiLevel cylinders offer affordable key control through patent-pending keys, without enhanced UL 437 attack resistance, which ensures you are not paying for high-security features that may not be needed for certain openings.

Key Control - Patent-pending key control protects against unauthorized duplication of keys through 2040.
  Protection against 3D Printing - A patent-pending movable element in the key deters unauthorized 3D printed copies of keys or blanks.
Picking and Bumping Protection - M4 high security cylinders use cylinder side pins, a shuttle lift pin and a movable element in the key to engage a sidebar to prevent opening until the elements are rotated and aligned in the correct position, protecting against bumping, picking and other attacks.
     Uses Existing Hardware - M4 cylinders are available in a wide variety of formats, retrofitting most hardware on the market.
Protection from Physical Attack - M4 high security cylinders are UL 437 listed for protection against drilling, picking, and other forms of physical attack.
Special Angled Key Cuts - A special key cutting machine and access to Medeco-specific blanks are required to duplicate M4 keys, which are available in multiple levels of restriction to support every need.

Master Keying Capabilities - M4 cylinders can be master keyed into a system that includes M4, BiLevel, and M4 CLIQ keys and cylinders. Very large systems are possible.


UL 437 Listed 

Tests prescribed in Underwriters Laboratory Standard 437 for Safety for Locks are primarily designed to measure a high security cylinder's ability to resist physical attack. 

Tests Include: 

Exceeds 100,000 cycle endurance testing

Resistant to picking or key fitting tests

Attack resistance tests

-Forcing, drilling, sawing, prying, pulling, plug driving, and corrosion resistance in a salt fog chamber.

While Medeco 4 high security cylinders meet or exceed UL 437 criteria, most common or standard cylinders available today do not meet these minimum guidelines.

ANSI/BHMA A156.30 & 156.5 Rated (pending)

Builders Hardware Manufacturing Association (BHMA) standard A156.30-2003, approved and adopted by ANSI, covers high security cylinders and was developed to provide specific guidance as to which products can be considered as high security cylinders. Medeco 4 cylinders meet or exceed BHMA A156.30 criteria for strength and durability, key control, and surreptitious entry resistance.


High Security Cylinder Features:

  • UL 437 Listed for physical protection 
  • Solid machined brass construction
  • Strategically placed drill pins to thwart drilling attacks
  • 4 Side pins in 3 depths for increased potential combinations 

Standard vs. High Security Cylinders

Key Features:

  • Movable element in key (shuttle pin) helps deter against unauthorized 3D copying   
  • Patented key control to help prevent unauthorized duplication
  • Angled, off-set cuts on key blade 
  • Medeco key machine and specific authorized blanks required to duplicate keys


  • M4 cylinders are available in a wide variety of formats and are ideal for any application requiring key control and a high level of physical security. Some of these applications include: critical infrastructure, government facilities, healthcare, data centers, public utilities, commercial and retail businesses.


  • Medeco 4 cylinders are warranted for two years against manufacturer's defects. See the Medeco® limited warranty for full details .


Medeco 4 has secured the following industry awards:


Medeco 4 Brochure

Medeco 4 Sell Sheet

Medeco 4 BiLevel Sell Sheet

Medeco 4 Sell Sheet (French)

Medeco 4 FAQs

Blog: What makes a true high security cylinder?

Blog: 3 Steps to Design a Convenient and Cost-Effective Security System

Blog: Protecting Against Security Threats of Today and Tomorrow - 3D Printing

The Evolution of High-Security Locking Systems: What You Need to Know Today

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