Medeco 310100K KeyMark 31 Seri...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$136.00
$117.01
Medeco Medeco KeyMark 31 Series Large Format Interchangeable Core (LFIC) for Yale, 8E Keyway 310100K

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

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Model: 310100K-26-8EP
$136.00
$117.01
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In Stock (leaves warehouse same day if ordered before 3pm ET)

$136.00
$117.01
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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.

Manufacturer Resources

Medeco Product Catalog

Product Specs

Product Group:
Parts and Accessories
Product Subgroup:
Cylinders
Product Type:
LFIC Cylinders
Compatibility:
Yale
Commercial/Residential:
Commercial
Subcategory:
Cylinders
Grade:
Grade 1
Duty Level:
Heavy Duty
Technology:
KeyMark
Keyway Options:
8E Keyway
Product Category:
Parts and Accessories
Product Substrate:
Brass
Department:
Door Hardware

Medeco 310100K-26-8EP – Frequently Asked Questions

1) Will a Medeco KeyMark 31 Series LFIC core drop into my existing Yale interchangeable core hardware?
Yes. The KeyMark 31 Series large format interchangeable core is built to retrofit Yale LFIC housings, and that covers mortise housings, rim cylinders, key-in-knob locks and padlock bodies. If the hardware is already LFIC-prepped for Yale, the core goes in without replacing the lock body. That is the whole point of the format: you pull the old core with a control key and seat the new one.
2) What is the difference between the Medeco 31 Series LFIC and a standard interchangeable core when it comes to master keying?
The 31 Series puts the control/locking lug at the back of the cylinder, operated by an extra-long key, instead of using a control shear line in the pin stack. No build-up or control pins are needed. Practically, that means an existing master key system that was never designed around interchangeable core pinning can absorb these cores without being rebuilt. On a conventional LFIC, the control pins constrain the pinning and often force a system redesign.
3) Can maintenance staff rekey a Yale LFIC lock without taking the door hardware apart?
Yes, and that is the reason to spec an interchangeable core. A control key removes the KeyMark core and a new core drops in, so the lock is effectively rekeyed in seconds with no disassembly and no locksmith on site. Property managers and facility teams use this for tenant turnover and lost-key events; non-technical personnel can do the swap. The cores themselves come pinned or sub-assembled depending on how your keying is handled.
4) Is the 8E keyway restricted, or can a hardware store copy the keys?
Keys for KeyMark cores on the 8E keyway are Medeco 4 (M4) patented keys, and they can only be duplicated by Medeco or an authorized Medeco service outlet, and only when the owner requests it. A tenant or employee cannot walk into a hardware store and get a copy. That is the reason facilities with turnover, healthcare, and government buildings spec KeyMark over an open keyway.
5) Will this Medeco core work in Schlage, Best, or Corbin interchangeable core hardware?
No. This is a large format interchangeable core cut for Yale LFIC housings specifically. Large format cores are not cross-brand interchangeable, and it will not seat in Best-style small format prep or another manufacturer's LFIC housing. If your hardware is not Yale LFIC, you need the Medeco KeyMark core built for that brand instead.
6) Can I put these cores on padlocks and rim exit devices as well as the door locks, all on one key?
Yes, as long as the hardware takes a Yale large format core. The same KeyMark core fits Yale LFIC mortise housings, rim cylinders, key-in-knob locks and padlock bodies, so gates, cabinets, exit device rim cylinders and entry doors can all run on one master key system. Order them keyed alike or master keyed to suit.
7) Do I order the Medeco KeyMark core pinned or sub-assembled?
Pinned means the core arrives keyed to your system and ready to install. Sub-assembled means it ships unpinned for a locksmith or an in-house shop with a Medeco pinning kit to key to an existing system on their own bench. If you do not maintain your own key records, order pinned. Cores can be keyed alike, keyed different, or master keyed.
8) Should I get the 6-pin or 7-pin Medeco KeyMark 31 Series core?
Both are offered, and the choice follows the key system you already run, not the door. A 7-pin core gives more differs and deeper masterkeying levels for a large facility; 6-pin is the standard KeyMark configuration. Cores in a single system have to share pin count and keyway, so match whatever is already cut into your existing KeyMark 8E keys.
9) What finish should I order to match the rest of the Yale hardware in the building?
Thirteen finishes are offered, so the core face can match the lock it sits in: 605 bright brass, 606 satin brass, 609 antique brass, 611 bright bronze, 612 satin bronze, 613 dark bronze oil-rubbed, 618 bright nickel, 619 satin nickel, 20 antique nickel, 622 flat black, 624 dark bronze, 625 bright chrome and 626 satin chrome. Most commercial openings are 626 satin chrome or 613 oil-rubbed bronze; read the number stamped on your existing trim and match it.
10) Do I need to buy a control key separately to swap Medeco KeyMark cores?
A control key is what removes the core, and on the 31 Series it is an extra-long key that throws the locking lug at the back of the cylinder. It is a separate item from the operating keys and it is issued as part of your keying setup, so specify it when you place the keying order if your facility does not already hold one for this system. Without it the core cannot be pulled.
How fast can I get the Medeco 310100K-26-8EP delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Medeco 310100K-26-8EP come with a warranty?
Absolutely. The Medeco 310100K-26-8EP is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Medeco 310100K-26-8EP?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
Why buy the Medeco 310100K-26-8EP from ZenSupply?
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