Medeco 310100J Bi-Level 31 Ser...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$112.89
Medeco Medeco Bi-Level 31 Series Large Format Interchangeable Core (LFIC) for Yale, DL Keyway 310100J

Medeco 310100J Bi-Level 31 Series Large Format Interchangeable Core for Yale DL Keyway

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Model: MED-310100J-26-DLT
$112.89
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$112.89
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Medeco 310100J Bi-Level 31 Series Large Format Interchangeable Core for Yale DL Keyway

The Medeco 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 Bi-Level (Medeco 4 / M4) cylinder technology with a DL keyway, this core allows non-technical personnel to quickly rekey locks using a special control key — no disassembly required. 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.

Key Features

  • Tool-Free Core Changeability: Cores can be quickly and easily changed by non-technical personnel using a special control key, effectively "rekeying" the lock without disassembly — reducing the cost of routine rekeying service calls.
  • UL437 Listed: Provides assurance that cylinders meet universal standards for drill and pick resistance and stand up to other types of forced attack.
  • 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 the need for build-up or control pins, simplifying pinning and enabling integration into existing master key systems not originally designed for interchangeable core pinning.
  • Yale LFIC Retrofit Compatibility: The 31 Series is specifically designed to retrofit Yale LFIC mortise housings, rim, key-in-knob, and padlock bodies for seamless upgrades to existing hardware.
  • Patented Medeco 4 (M4) Bi-Level Technology: Keys may only be duplicated by Medeco or an authorized Medeco service outlet and only at the owner's request, providing utility patented key control.
  • Durable Machined Brass Construction: All cylinder components are constructed of machined brass, designed to last the life of the equipment in demanding commercial environments.
  • Flexible Keying Options: Cylinders can be ordered keyed alike, keyed different, or master keyed to accommodate a wide range of security system configurations.
  • Multiple Finish Options: 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 Certified
  • BHMA Grade 1
  • Heavy Duty Commercial Rating

Technical Specifications

  • Series: 31 Series Large Format Interchangeable Core (LFIC)
  • Cylinder Technology: M3 BiLevel
  • Pinning: 6-Pin
  • Keyway: DL 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
  • Educational Facilities
  • Healthcare Institutions
  • Government and Municipal Buildings
  • Retail Establishments
  • Industrial and Warehouse Facilities
  • Multi-Tenant Residential and Mixed-Use Properties

Why Medeco?

Medeco 31 Series LFIC cylinders are built from durable machined brass components and carry a UL437 listing for verified drill and pick resistance, delivering professional-grade security for demanding commercial applications. The patented Medeco 4 Bi-Level key control system ensures that key duplication is strictly controlled, while the back-of-cylinder lug design simplifies pinning and master key system integration — making the 31 Series a trusted choice for facilities requiring both high security and operational flexibility.

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:
Bilevel
Keyway Options:
DL Keyway
Product Category:
Parts and Accessories
Product Substrate:
Brass
Department:
Door Hardware

Medeco MED-310100J-26-DLT – Frequently Asked Questions

1) Will a Medeco 31 Series LFIC core drop into my existing Yale interchangeable core hardware?
Yes. The 31 Series large format interchangeable core is built to retrofit Yale LFIC housings, including mortise housings, rim cylinders, key-in-knob locks, and padlock bodies. If the opening is already LFIC-prepped Yale hardware, the core swaps in without replacing the lock body.
2) Can building staff rekey a Medeco LFIC core themselves without pulling the lock apart?
That is the point of an interchangeable core. A control key pulls the core out and a new one drops in, so a maintenance tech with no locksmith training can effectively rekey the door in seconds, with no disassembly of the lock. For a property manager turning units or a facility handling a lost-key event, that removes the service call.
3) Do I order the Medeco 310100J in 6-pin or 7-pin?
Both are offered on the 31 Series DL core. Match the pin count to the master key system you are already running, since the core has to pin into that system's bitting. The 31 Series puts its control/locking lug at the back of the cylinder, activated by an extra-long control key, which means no build-up or control pins are needed and it can be folded into a master key system that was never designed around interchangeable cores.
4) What is the difference between ordering a Medeco core pinned versus sub-assembled?
Pinned means the core arrives loaded to a keying assignment and is ready to install. Sub-assembled means it comes for your locksmith or in-house shop to pin to your own system. Facilities that maintain their own key records take sub-assembled; anyone who wants the core to work out of the box takes pinned. Keying can be set up keyed alike, keyed different, or master keyed.
5) Can someone copy a Medeco M4 Bi-Level key at a hardware store?
No. The Bi-Level (Medeco 4) system is utility patented, and keys may only be duplicated by Medeco or an authorized Medeco service outlet, and only at the key system owner's request. That is the reason institutions with a controlled key policy specify it: a departing tenant, contractor, or employee cannot walk into a kiosk and cut a spare.
6) Will a DL keyway core work with the keys we already carry?
Only if your existing Medeco system is cut on the DL keyway, which is the Yale-family keyway this core is built around. A core in one keyway will not accept keys from another, so ordering DL when the rest of the building runs a different keyway leaves you carrying two key rings. Check what your key records say before you standardize a floor or a campus on it.
7) Is this a whole lock or just the cylinder core?
It is the core only, not a complete lockset. It is the removable cylinder that carries the pins and accepts the key, and it goes into a Yale LFIC housing you already have or buy separately. If the door has no LFIC-prepped hardware on it yet, you need the mortise housing, rim cylinder body, knob, or padlock body as well.
8) Is a large format interchangeable core the right choice, or should I use small format?
Large format is what you use when the existing hardware is prepped for it, which on Yale openings is common in commercial buildings. The two are not interchangeable: an SFIC core will not seat in an LFIC housing and vice versa, so the prep already in the door decides it, not preference. Pull one core out with the control key and look at it before you order a building's worth.
9) What finishes does the Medeco 31 Series LFIC come in, and can I match the trim already on my doors?
Thirteen finishes: 605 bright brass, 606 satin brass, 609 antique brass, 611 bright bronze, 612 satin bronze, 613 dark bronze oil-rubbed, 624 dark bronze, 618 bright nickel, 619 satin nickel, 20 antique nickel, 622 flat black, 625 bright chrome, and 626 satin chrome. Satin chrome (626) and satin nickel (619) are the usual matches for commercial lever trim.
How fast can I get the Medeco MED-310100J-26-DLT 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 MED-310100J-26-DLT come with a warranty?
Absolutely. The Medeco MED-310100J-26-DLT 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 MED-310100J-26-DLT?
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 MED-310100J-26-DLT from ZenSupply?
ZenSupply makes it easy to get the commercial door hardware you need—fast shipping, expert support, and rewards on every order. Our team is always ready to help you choose the right product for your project.
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