Medeco Cylinders and Keys: How to Identify M3, X4 and KeyMark and Read Part Numbers

When you replace a Medeco cylinder or core, or order keys for an existing system, the part number has to be right. It encodes the cylinder type and size, the key technology (such as M3, X4 or KeyMark), the finish, the keyway and the pinning, and key blanks have their own KYB numbers. Below we read those numbers and explain how Medeco key control works, based on Medeco's 2026 U.S. product catalog.

Medeco M3, X4 and KeyMark: the key technologies

The catalog's key control chart gives a patent expiration date for six Medeco key technologies, and its how-to-order pages give each one a letter used in part numbers:

For Medeco3, Biaxial and Original the chart recommends upgrading to Medeco 4. Other letters cover BiLevel (P, J) and Intelligent Key versions (S, C, M, G).

X4 and KeyMark share catalog pages: the 6-pin SFIC 33600006 is listed as a Medeco X4 and KM 6 Pin SFIC, and the X4 and KM key drawings in the catalog's chart of Medeco X4 keys carry the name KeyMark by Medeco. Medeco B is a separate line of unpatented SFIC cores in industry standard SFIC keyways.

How to identify a Medeco cylinder or key

• The part number. The catalog states that complete part numbers are required for all orders, so start from the full number.
• The key. In the key drawings of the catalog's key charts, Medeco 4 keys carry an M4 mark and Medeco3 keys an m3 mark. The chart adds that Medeco keys not found on it are most likely from an original equipment manufacturer using Medeco products; for duplicate keys, it sends you back to the original manufacturer of the product.

How to read a Medeco part number

For rim and mortise cylinders the catalog orders the fields as base part number, technology, finish, keyway, pinning, cam or tailpiece, plus a side pin code for M4 only. Its own example is 100200 H 05 M4 P Z01 624. Our Medeco 100200T-26-DLT-Z01 reads:

• Length: the mortise base number sets it, for example 100500 is 1-1/4 inch and 105400 is 1-3/4 inch.
• Cam: cams are listed by type, such as CT-Z02 Adams Rite type. If none is specified, the catalog says Z01 is supplied for mortise and Y02 for rim cylinders.
• Pinning: codes include S sub-assembled (uncombinated), P pinned (combinated) and M master keyed. T and Q mean pinned and sub-assembled for the M3 programs DL (DND Program) and DM (NYC Program) only.
• Finish: the finish chart pairs codes with US numbers, such as 24 Dark Bronze with Clear Coat (US20A). See our finish codes chart.

Key-in-knob, LFIC, SFIC and deadbolt numbers

• Key-in-knob and key-in-lever cylinders use the same order without the cam: 20200H1W-26-G3S is 20200H1 (Arrow and Schlage packages combined), W (Biaxial), 26, G3 keyway, S.
• LFIC numbers begin with the format being retrofitted: 32 for Medeco, 322201 for Schlage, 322301 or 322801 for Corbin Russwin, 322401 for Sargent, 310100 or 310100A for Yale. 322401T-26-DLQ is a 6-pin Sargent format core in M3. See SFIC vs LFIC.
• X4 SFIC cores read 33, pins (6 or 7), 00006, technology, finish, keyway, pinning: 33600006-N-26-DGVS is a 6-pin X4 core in the DGV keyway, sub-assembled; 33600006-K-26-6AS is a KeyMark (K) core in the 6A keyway.
• Maxum deadbolt base numbers read 11, trim (C commercial, R residential), cylinder type, function, bolt option and technology: 11C626T-26-DLT is commercial, Medeco 6 pin, cylinder x cylinder, 2-3/4 inch backset with round front, M3, then 26, DL, T. Medeco deadbolt parts listed in the same section include 110A04 (6 pin outside cylinder assembly) and CP-180061 (strike).

Medeco X4 key blanks and other key blanks

A selection from the catalog's custom coined door hardware key blanks (first part of each number as printed):

Our X4 blanks KYB-326900-DGV-44 (6-pin) and KYB-327900-DGV-44 (7-pin) are small bow blanks in the DGV keyway. For 60 Series cam locks the catalog lists non custom coined 5-pin Original blanks KYB 115400 (thick head) and KYB 105400 (thin head). Keyways in general: our key blank chart.

How Medeco key control works

The catalog says that stamping "Do Not Duplicate" on a key merely warns someone not to copy the key and is not a promise of legal protection or enforcement. It adds that every restricted Medeco key blank is custom coined and tracked by Medeco to identify it as an authorized key blank. Its programs include:

• Dealer or Service Center: the security professional who sold the locks keeps a signature card completed by the key system owner.
• Card Programs: card holders present a signed card to a participating Medeco security professional.
• Commercial: keys from any Medeco locksmith without specific authorization.
• Factory: additional keys only from the Medeco factory, with the proper signature.

In the key charts, symbols show how permission for copying keys is given and where keys are cut. The Medeco3 DND and NYC programs (the pinning codes list DL as the DND Program) are marked with a signed authorization card matched to identification, and keys cut at a regional service center and shipped back to the dealer. The X4 Dealer and KM/X4 End-User programs are marked with identification and signature verification, and keys cut on site by contracted dealers or end users.

Authorization cards have catalog numbers too, such as CARD XX 66 XX for a card with two 6 pin keys (Patriot, Liberty, GLD, DND, Freedom, Gotham); our CARD-DD-66-DL is listed as an authorization card for 6-pin M3 DL with 2 keys.

Medeco cylinders and keys at The Builders Supply

• Our Medeco brand page, plus High Security Cylinders and Cylinders & Cores
• M3: 11C626T-26-DLT double cylinder deadbolt, 322401T-26-DLQ LFIC core, Sargent format
• Biaxial: 20200H1W-26-G3S cylinder for Arrow and Schlage locks
• X4 and KeyMark: 33600006-N-26-DGVS X4 SFIC core, 33600006-K-26-6AS KeyMark SFIC core, KYB-327900-DGV-44 X4 key blank

For keys, blanks or cores for an existing system, contact us with the full part number and your Medeco key program, which decides how permission for more keys is given.

Not sure which Medeco technology or keyway you have? Our customer support team is available Monday - Friday, 8 AM - 4 PM Central Time, at 1-888-800-7789 or [email protected].