Medeco 310100T M3 31 Series La...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$192.00
$187.54
Medeco M3 31 Series Large Format Interchangeable Core (LFIC) for Yale, DL Keyway

Medeco 310100T M3 31 Series Large Format Interchangeable Core for Yale DL Keyway

(No reviews yet) Write a Review

Model: MED-310100T-26-DLT
$192.00
$187.54
Selected Finish is

In Stock (leaves warehouse same day if ordered before 3pm ET)

$192.00
$187.54
Adding to cart… The item has been added
Free Shipping on orders over $199
We price match and offer bulk discounts! Click Add to Quote. It's quick and easy.
✨
Earn points with this purchase! You can redeem points for giftcards, iPads, XBox's and more. View Rewards
Free Keying on all locks
You may also like

Medeco 310100T M3 31 Series Large Format Interchangeable Core for Yale, DL Keyway

The Medeco M3 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 DL keyway and Medeco's M3 technology, 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.
  • 31 Series Control 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.
  • UL437 Listed: Provides assurance that cylinders meet universal standards for drill and pick resistance and stand up to other types of forced attack.
  • 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.
  • Machined Brass Construction: Cylinders are constructed of durable machined brass components, designed to last the life of your equipment in demanding commercial environments.
  • Patented Key Control: Medeco 4 (M4) keys may only be duplicated by Medeco or an authorized Medeco service outlet, and only upon your request — providing superior key control and security.
  • Flexible Keying Options: Locks can be keyed alike, keyed different, or master keyed depending on your specific security 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 Certified
  • ANSI/BHMA Grade 1
  • Heavy Duty Commercial Rating

Technical Specifications

  • Series: 31 Series Large Format Interchangeable Core (LFIC)
  • Cylinder Technology: Medeco M3
  • 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 and Campuses
  • Healthcare Institutions and Hospitals
  • Government and Municipal Buildings
  • Retail Establishments
  • Industrial and Warehouse Facilities
  • Multi-Tenant Residential and Mixed-Use Properties

Why Medeco?

Medeco M3 31 Series LFIC cylinders deliver professional-grade security through durable machined brass construction, UL437-listed drill and pick resistance, and a patented key control system that restricts unauthorized key duplication. The back-of-cylinder control lug design simplifies pinning and master key integration, making the 31 Series an ideal choice for demanding commercial applications where reliable, manageable access control is essential.

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:
M3
Keyway Options:
DL Keyway
Product Category:
Parts and Accessories
Product Substrate:
Brass
Department:
Door Hardware

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

1) Will a Medeco M3 31 Series LFIC core drop into my existing Yale interchangeable core hardware?
That is exactly what the 31 Series is built for. The M3 large format interchangeable core retrofits Yale LFIC mortise housings, rim cylinders, key-in-knob locks, and padlock bodies, so any opening already prepped for a Yale large format core takes it without replacing the lock body. Pull the old core with the control key, drop this one in.
2) Do I need a locksmith to rekey a Medeco 31 Series interchangeable core?
No. Cores are changed by non-technical personnel with a special control key, no disassembly of the lock required. For a property manager turning units or a facility handling a lost-key event, that means swapping a core instead of booking a service call for every cylinder.
3) What is different about the Medeco 31 Series control lug compared with other interchangeable cores?
The control and locking lug sits at the back of the cylinder and is operated by an extra-long control key. Because of that placement there are no build-up or control pins to figure into the pinning, which is what lets the 31 Series fold into an existing master key system that was never laid out for interchangeable core pinning in the first place. If you are extending a legacy MK system rather than starting one, that is the practical reason to pick this series.
4) Can I order Medeco 31 Series cores unpinned so my locksmith can key them to our system?
Yes. Cores ship either pinned or sub-assembled. Sub-assembled is the one to order when your own locksmith or in-house security shop is pinning cores to an established Medeco master key system; pinned is the choice when you want them keyed and ready to install.
5) What keyway does the Medeco 310100T core use, and can it be keyed alike with my other Medeco cylinders?
The core is cut on the Medeco DL keyway with M3 technology. Cores can be keyed alike, keyed different, or master keyed, so a run can be set up to open on one key across a building or split by tenant. Any other cylinder you want on the same key has to be the same M3 platform and DL keyway.
6) Are Medeco M3 cores drill and pick resistant, and what grade are they?
UL437 Listed for drill and pick resistance and other forced attack, and ANSI/BHMA A156.5 Grade 1, heavy duty commercial. Construction backs that up: solid brass with nickel-plated pins and hardened stainless-steel drill-resistant pins. For a school district or hospital writing Grade 1 into the spec, this core meets it on the cylinder side.
7) Is this a full lock or just the core?
Just the core. The 310100T is the interchangeable cylinder that seats into hardware already prepped for a Yale large format core. It does not include the mortise housing, rim cylinder body, knob, or padlock, and it will not convert a lock that has a standard fixed cylinder to interchangeable core. If the door is not already LFIC prepped, you need the matching housing or a lock body first.
8) Is the Medeco M3 LFIC core available in 6-pin and 7-pin?
Both. The 31 Series core is offered as a 6 pin or a 7 pin cylinder. Match the pin count to the rest of your master key system, since the pinning depth on your existing Yale system decides which one keys in correctly.
9) Can our tenants get Medeco keys copied at a hardware store?
No. Medeco keys are duplicated only by Medeco or an authorized Medeco service outlet, and only at your request. That patented key control is the reason facilities with turnover, contractor access, or after-hours cleaning crews specify Medeco instead of a standard cylinder, since an unauthorized copy is the failure mode a rekey cannot prevent.
10) What finishes does the Medeco M3 31 Series LFIC core come in?
Thirteen finishes, so the core face matches the trim already on the door: 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. On most commercial openings 626 Satin Chrome or 626-adjacent 619 Satin Nickel is what the existing Yale hardware wears.
11) Will Medeco M3 cores hold up in high-traffic commercial doors?
They are built for it. The cylinders are machined brass throughout and carry a heavy duty commercial rating, which is the durability class you want on an entrance, a stairwell, or a tenant suite door cycling all day. This is not a residential-grade core.
How fast can I get the Medeco MED-310100T-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-310100T-26-DLT come with a warranty?
Absolutely. The Medeco MED-310100T-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-310100T-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-310100T-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.
!