Medeco 310100K KeyMark 31 Series Large Format Interchangeable Core (LFIC) for Yale, 8E Keyway

Medeco KeyMark 31 Series Large Format Interchangeable Core (LFIC) for Yale, 8E Keyway

The Medeco KeyMark 31 Series Large Format Interchangeable Core (LFIC) is a heavy-duty, Grade 1 commercial cylinder engineered to retrofit Yale LFIC mortise housings, rim, key-in-knob, and padlock bodies. Featuring the KeyMark technology with the 8E keyway, this LFIC allows non-technical personnel to quickly swap cores using a special control key — effectively "rekeying" a lock without disassembly. Constructed of durable machined brass components, the 31 Series positions its control/locking lug at the back of the cylinder, eliminating the need for build-up or control pins and simplifying integration into existing master key systems not originally designed for interchangeable core pinning.

Key Features

• Quick Core Changeability: Non-technical personnel can remove and replace cores using a special control key, effectively rekeying the lock without disassembly — reducing the cost of routine rekeying service calls.
• 31 Series Control/Locking Lug Design: The control/locking lug is positioned at the back of the cylinder, activated by an extra-long key. This eliminates build-up or control pins, simplifying pinning and enabling retrofit into existing master key systems not designed for interchangeable core pinning.
• Yale LFIC Compatibility: Designed specifically to retrofit Yale LFIC mortise housings, rim cylinders, key-in-knob locks, and padlock bodies for seamless integration into existing Yale hardware.
• UL437 Listed: Provides assurance that cylinders meet universal standards for drill and pick resistance, standing up to forced attack attempts.
• Patented KeyMark Key Control: Medeco 4 (M4) patented keys may only be duplicated by Medeco or an authorized Medeco service outlet, and only upon the owner's request — providing superior key control.
• Durable Machined Brass Construction: Cylinders are constructed of durable machined brass components, designed to last the life of the equipment in demanding commercial environments.
• Flexible Keying Options: Locks can be keyed alike, keyed different, or master keyed to accommodate a wide range of security and access management requirements.
• Wide Finish Selection: Available in 13 finishes including Bright Brass, Satin Brass, Antique Brass, Bright Bronze, Satin Bronze, Oil Rubbed Bronze, Bright Nickel, Satin Nickel, Antique Nickel, Black, Dark Bronze, Bright Chrome, and Satin Chrome.

Certifications & Compliance

• UL437 Listed — Drill and Pick Resistance
• ANSI/BHMA Grade 1
• Heavy Duty Commercial Rating

Technical Specifications

• Series: 31 Series Large Format Interchangeable Core (LFIC)
• Cylinder Technology: Medeco KeyMark (KM)
• Pinning: 6-Pin
• Keyway: 8E Keyway
• Certification: ANSI/BHMA A156.5 Grade 1 rated hardware platform
• Construction: Solid brass construction with nickel-plated pins and hardened stainless-steel drill-resistant pins
• Compatibility: Retrofits into existing LFIC-prepped hardware without replacement
• Warranty: 2-year manufacturer's warranty

Typical Applications

• Commercial Office Buildings with Yale LFIC Hardware
• Educational Facilities Requiring Frequent Rekeying
• Healthcare Institutions with Master Key Systems
• Retail Establishments Needing Key Control
• Government and Municipal Buildings
• Multi-Tenant Residential and Mixed-Use Properties
• Industrial and Warehouse Facilities with High-Security Requirements

Why Medeco?

Medeco KeyMark 31 Series LFIC cylinders deliver professional-grade security through durable machined brass construction, UL437-listed drill and pick resistance, and patented key control that restricts unauthorized key duplication to Medeco-authorized outlets only. Engineered for demanding commercial applications, the 31 Series simplifies master key system integration and reduces operational rekeying costs — making it a trusted choice for facilities managers and security professionals alike.