What Do the Numbers on a Cast Iron Skillet Mean?
The large number on a cast iron skillet is a size designation, not a diameter. Other numbers and letters on the base identify the pattern, the catalog entry or the worker who made the mold. Where a mark sits and how it is formed tell you which kind it is.
| Mark | Looks like | What it tells you |
|---|---|---|
| Size number | A large numeral on top of the handle or on the base | The maker's size. Not inches. |
| Pattern number (Griswold) | A three- or four-digit number on the base, such as 704 | The model and size of the pattern |
| Catalog number (Wagner) | Four digits, often with a letter, such as 1053C | Model, size and working pattern |
| Pattern letter | A single letter near the number | Which working pattern was used. Not age or quality. |
| Molder's mark | A small raised letter or number, sometimes off-center | The individual molder or shift |
| Size in inches | Text such as 10 5/8 IN. | Generally 1950s or later |
Size numbers
Nearly all vintage skillets carry a large numeral. Measure the rim and you will find it matches neither the top nor the bottom diameter. The numbering traces back to the “eyes” of wood-burning stoves and stayed in use long after gas and electric stoves took over. Dimensions also varied by maker: a Martin No. 3 matches a Wagner No. 2, and some makers cast their pans slightly wider to seem larger.
Griswold pattern numbers
Griswold skillets carry a pattern number as well as a size. The numbers do not follow the sizes in any obvious way: a No. 6 is 699, a No. 7 is 701 and a No. 8 is 704. In rare cases a pattern number is not unique to one model, and early ERIE skillets show several numbers for the same size.
Wagner catalog numbers
Wagner used catalog numbers that encode the model and size, usually followed by a pattern letter. In 1053C, 105x is a regular skillet, the final 3 is the size, and C is the working pattern. Two-digit sizes continue the series, so No. 10 through No. 14 skillets are 1060 through 1064. Wagner also duplicated some catalog numbers.
Pattern letters and molder's marks
Foundries cast popular sizes from many working patterns at once and gave each one a letter, so a flawed casting could be traced to a worn pattern. The letters do not mark design revisions, and none is better than another. A pan with no letter was simply cast from a different pattern.
Molder's marks are different: small raised letters or numbers added to the mold itself, often sitting slightly askew. Tiny numerals, typically 1 to 4, under the handle of small pans identify positions in a gang mold.
Later marks
From the late 1950s or early 1960s Lodge used letters for models rather than patterns, such as DO for Dutch oven. Sizes spelled out in inches appear from around the 1950s and usually indicate a later, less collected piece, with a few exceptions.
Sources: The Cast Iron Collector: Numbers and Letters
Updated 2026-11-10. How we check and correct this site.