Reading Key Blank Cross-References (Ilco, JMA, Silca)

Order the same key blank from three suppliers and you may get three different codes on three different bags — and all three parts will be identical. Every established blank carries an Ilco number, a JMA number, a Silca number and usually an OEM part number on top, because there has never been a single universal registry for key blanks. The cross-reference is the translation table between those systems, and reading one fluently is what separates a tight, fast-moving blank inventory from a drawer of dead stock.

Why One Blank Has Several Names

Key blank manufacturers each number their own catalogs, and those catalogs grew up independently over decades. A blank that Ilco released under one code was later matched by JMA and Silca under their own codes, while the automaker kept selling the same profile under a dealer part number. Add the fact that Ilco itself often lists two codes for a single blank — a traditional code and a parallel "X" number — and it's completely normal for one piece of brass to be referenced five different ways, all of them correct.

None of this changes the metal. The keyway profile, blade length and cut spacing are properties of the blank itself; the codes are just addresses for finding it in different catalogs.

The Big Three Reference Systems

Ilco. The default reference system in North America, and the one most US and Canadian locksmiths quote from memory. Ilco runs two numbering schemes side by side: traditional codes that group blanks by make and keyway family, and the sequential EZ "X" numbers used as catalog shorthand. Ilco and Silca now sit under the same corporate parent (dormakaba), but their numbering systems remain fully separate.

Silca. The dominant European reference. Silca codes combine a make prefix with a profile number, and because Silca data ships inside key machines and software sold worldwide, its codes turn up constantly in North American listings too.

JMA. A Spanish manufacturer with a strong footprint across the Americas. JMA codes also use a make prefix plus a number, with letter suffixes marking variants of a base profile.

OEM numbers. The automaker's own part number is the most precise identifier for a specific vehicle, year and head style — and the least useful for organizing a shelf, since one keyway can hide behind dozens of OEM numbers. OEM references matter most when a customer or dealer hands you their number and you need to translate it into something you stock.

How to Read a Typical Cross-Reference Listing

A listing for a common Toyota blank might read like the table below. Treat it as a representative example of the format — always confirm specific codes against the current Ilco, JMA and Silca catalogs before ordering.

Every row describes the same piece of brass. When a supplier's listing shows a string like "TR47 / X217 / TOYO-15D / TOY43," it isn't listing four products — it's telling you that whichever catalog you think in, this is the blank you mean.

Anatomy of an Ilco Code

Ilco's traditional codes carry real information once you know the pattern:

• The letters name the keyway family, usually by make. TR for Toyota, HD for Honda, B for General Motors, H for Ford, HY for Hyundai and so on. Blanks sharing a letter prefix belong to the same manufacturer's lock ecosystem, though not necessarily the same keyway.
• The number distinguishes the variant — a different keyway generation, blade length or head style within that family.
• The X numbers are pure catalog sequence. An EZ number like X217 encodes nothing about the make; it's shorthand that maps one-to-one onto a traditional code.
• Suffixes flag electronics. A "-PT" suffix marks a transponder-equipped version of a blank — Ford's H72-PT is a classic example — and some transponder blank codes fold the chip type into the name, like TOY43AT4 for a Toyota blade carrying a Texas 4D chip.

Transponder Blanks vs Mechanical-Only Blanks

The same blade profile frequently exists in two forms: plain brass, and a chip-carrying version with a plastic head. The mechanical-only blank is the right call for pre-immobilizer vehicles, for door, trunk or glovebox keys, and for non-starting service copies. It is the wrong call for anything that has to start a chipped car — a mechanically perfect blank with no chip is the classic crank-no-start callback.

The suffix conventions above tell you a chip is present, but not that it's the right chip: transponder generations changed several times within most makes, and a 4C-era blank in a 4D-era application fails the immobilizer handshake just as thoroughly as no chip at all. Our guide to transponder keys, chips and programming covers how to match the chip family to the vehicle.

How Cross-Refs Prevent Wrong Orders and Dead Stock

Key blanks are full of near-twins: profiles that look alike in silhouette but differ by a groove position measured in fractions of a millimeter, which is exactly enough to keep a blade out of a keyway. Ordering by eye — "it looks like the Toyota one" — is how boxes of fifty unusable blanks end up at the back of the van.

Cross-references eliminate the guesswork, and they earn their keep in a few specific ways:

• Substituting across brands. When your preferred line is out of stock, the cross-ref tells you exactly which JMA or Silca code is the same blank, so the substitution is a fact rather than a hope.
• Consolidating what you already own. Bags bought from different suppliers under different codes often turn out to be one blank — cross-referencing your own drawers frees up money you've already spent.
• Quoting from whatever the customer has. A dealer part number, an old invoice code or a competitor's SKU can each be translated into the blank you actually stock.

Cross-References at Car Key Source

Every listing at Car Key Source carries the brand, the manufacturer part number, the FCC ID where the part includes a remote, and cross-references where they apply — so you can search with whichever code you know and land on the same part. We stock the genuine Ilco line alongside Strattec OEM hardware, and you can browse blanks, remotes and keys by category or start from the vehicle itself in Find My Fob when all you have is a year, make and model.

Cross-Reference FAQ

Are cross-referenced blanks identical?

Mechanically compatible — not necessarily identical. A cross-reference asserts that the blade fits the same keyway and accepts the same cuts. Brass alloy, head shape, plating and price can all differ between manufacturers, and on transponder blanks the cross-reference says nothing about the chip: the chip family still has to match the vehicle generation separately.

What if a code doesn't appear in one catalog?

It happens constantly — no catalog covers every blank, and regional coverage differs between the big three. A missing Silca code doesn't mean the blank doesn't exist; it means that catalog never assigned one. Pivot to another reference system, fall back to the OEM number, or search by vehicle application instead.

Car Key Source supplies professional locksmiths in the US and Canada with genuine Ilco and Strattec parts at trade-only wholesale pricing — every listing identified by part number, FCC ID and cross-reference, and backed by our exact-fit guarantee. Orders placed by 4 PM ET ship the same day. Apply for a trade account or get an instant quote on your stocking list.