Serial number decoder
Farmall plates carry more than a number: a prefix that names the model, sometimes a plant letter that changes which table the number belongs to, and option codes after the digits. The decoder handles all three and shows its bracket.
Pick the brand, pick the model, type the number exactly as stamped. The answer shows the bracket your number fell in and the sources behind it.
These are the exact tables the decoder reads from — every one assembled from two independent published sources. Check our work.
Where the number is: On the aluminum serial plate riveted to the left side of the clutch (bell) housing. The same number is stamped on a flat pad on the engine. Very early 1939 tractors may have the number stamped on the frame rail instead of a plate.
| Model year | First serial | Last serial |
|---|---|---|
| 1939 | 501 | 10,652 |
| 1940 | 10,653 | 52,386 |
| 1941 | 52,387 | 93,236 |
| 1942 | 93,237 | 122,589 |
| 1943 | 122,590 | 150,250 |
| 1944 | 150,251 | 186,122 |
| 1945 | 186,123 | 214,819 |
| 1946 | 214,820 | 241,142 |
| 1947 | 241,143 | 268,990 |
| 1948 | 268,991 | 300,875 |
| 1949 | 300,876 | 327,974 |
| 1950 | 327,975 | 351,922 |
| 1951 | 351,923 | 375,860 |
| 1952 | 375,861 | 390,499 |
| 1953 | 390,500 | 391,730 |
Sources: Yesterday's Tractors serial lists (IH records / Guy Fay data-book lineage); Tractor & Construction Plant Wiki Farmall H table (Wisconsin Historical Society records) — identical.
Where the number is: Aluminum plate on the left side of the clutch housing, prefix SH. Engine number stamped on the block pad; a Super H engine carries the C-164 marking.
| Model year | First serial | Last serial |
|---|---|---|
| 1953 | 501 | 22,201 |
| 1954 | 22,202 | 29,285 |
Sources: Yesterday's Tractors serial lists and Super H production figures (21,916 built 1953; 10,052 built 1954).
Where the number is: Aluminum plate on the left side of the clutch housing, prefix FBK. Engine serial stamped on the flat pad on the engine block near the No. 1 spark plug.
| Model year | First serial | Last serial |
|---|---|---|
| 1939 | 501 | 7,239 |
| 1940 | 7,240 | 25,370 |
| 1941 | 25,371 | 50,987 |
| 1942 | 50,988 | 60,010 |
| 1943 | 60,011 | 67,423 |
| 1944 | 67,424 | 88,084 |
| 1945 | 88,085 | 105,563 |
| 1946 | 105,564 | 122,822 |
| 1947 | 122,823 | 151,707 |
| 1948 | 151,708 | 180,513 |
| 1949 | 180,514 | 213,578 |
| 1950 | 213,579 | 247,517 |
| 1951 | 247,518 | 290,922 |
| 1952 | 290,923 | 298,218 |
Sources: Tractor & Construction Plant Wiki Farmall M table (Wisconsin Historical Society records); Yesterday's Tractors serial list — identical.
Where the number is: Plate on the left side of the clutch housing. The first letter is the plant: F for the Farmall Works, L for Louisville — the two plants ran separate number series, so the plant letter decides which table your number belongs to.
| Model year | First serial | Last serial |
|---|---|---|
| 1952 | 501 | 12,515 |
| 1953 | 12,516 | 51,976 |
| 1954 | 51,977 | 59,947 |
| Model year | First serial | Last serial |
|---|---|---|
| 1952 | 500,001 | 501,905 |
| 1953 | 501,906 | 600,000 |
| 1954 | 600,001 | 65,415 |
Sources: Yesterday's Tractors Super M serial list (both plant series), forum-verified against IH production figures.
Where the number is: Plate on the seat support (toolbox), prefix FC. All C serials are five digits; six digits means Super C.
| Model year | First serial | Last serial |
|---|---|---|
| 1948 | 501 | 22,623 |
| 1949 | 22,624 | 47,009 |
| 1950 | 47,010 | 71,879 |
| 1951 | 71,880 | 80,432 |
Sources: Yesterday's Tractors Farmall C serial list; production records (last C = 80432).
Where the number is: Plate riveted to the seat support / battery box side, prefix FC. Six-digit number — that alone separates it from the C.
| Model year | First serial | Last serial |
|---|---|---|
| 1951 | 100,001 | 131,156 |
| 1952 | 131,157 | 159,129 |
| 1953 | 159,130 | 187,787 |
| 1954 | 187,788 | 198,310 |
Sources: Tractor & Construction Plant Wiki Farmall Super C table; Yesterday's Tractors production figures (last Super C = 198310) — identical.
Where the number is: Serial plate on the left side of the seat support. A tractors use the FAA prefix family; B tractors share the same number series.
| Model year | First serial | Last serial |
|---|---|---|
| 1939 | 501 | 6,743 |
| 1940 | 6,744 | 41,499 |
| 1941 | 41,500 | 80,738 |
| 1942 | 80,739 | 96,389 |
| 1944 | 96,390 | 113,217 |
| 1945 | 113,218 | 146,699 |
| 1946 | 146,700 | 182,963 |
| 1947 | 182,964 | 198,298 |
Sources: Yesterday's Tractors Farmall A/B serial list (IH records lineage).
Every major IH casting carries a date code like 1·29·J — month, day, and a year letter (I = 1939, J = 1940, and so on). If the castings cluster a few months before your serial's year, the tractor hangs together. If they are years apart, parts have been swapped. Read the IH casting date code.
The decoder gives you the year. The kit gives you the rest of the check before money changes hands: serial-verification worksheets, the two-numbers check that catches swapped engines, year-split parts traps, and an inspection checklist for each family.
Included in the $39 Buyer's Check Kit