How to Find Your Tractor’s Birthday

My mom inherited a 1939 Farmall M from my grandpa a couple of years ago. It’s a beauty of a tractor, and the happy memories of riding it with my grandpa make it all the more special. I’m sure many of you feel the same way about a special tractor that belonged to someone you care about.

If you are looking for an excuse to celebrate your favorite tractor (and who wouldn’t?), find your tractor’s date of manufacture and throw a birthday party! Here’s how to do so for Farmall tractors. 

Many of you probably already know how to find the year of your tractor’s manufacture by looking up the serial number. My app, Tractor Guide, and plenty of written guides, like what’s in the Steiner catalog or in other books, can match the year with the serial number. But if you are going to throw a birthday party, you’ve got to get more specific than that!

Farmall and IH tractors have dates cast right into key parts that indicate their precise dates of “birth” (or rather, the date the parts were cast in the foundry). Of course, most parts would be seasoned for several weeks before being machined and assembled into a tractor – making the actual manufacture completion date of a tractor a month or so after the parts were cast.

It takes a little bit of discifering to determine your tractor’s casting day, but once you catch on it’s not too hard.

The first two numbers in the code are the month and day – for example: “6 11” is June 11 and “12 5” is December 5. To determine the year, look at the last letter in the series. Add the number of that letter’s place in the alphabet (A = 1, B = 2, C = 3, and so on) to 1930 to determine the year. Here’s an example: The letter I is number 9 in the alphabet. When you add 9 to 1930, you get 1939 – the year of our sample tractor’s manufacture. At the end of the article is a table to make it a little easier, along with a couple of exceptions to the letter/year system. 

Of course, your tractor might have a couple of parts with different casting dates on them. It’s also entirely possible that a part with a date code has been swapped with a part from another tractor. But if you are looking for a day to throw a birthday party, I go by the date stamped on the block – that seems to be the heart of the tractor to me. It’s also the easiest to find!

This can be a lot of fun. Perhaps you’ll find a tractor that shares your birthday, or the birthday of someone in your family!

You might also find tractor twins – I did! We bought a Farmall H sight-unseen from an online auction a year or two ago. When my Dad and I went to pick up the tractor, we were delighted to see that everything was in proper working condition. Out of a moment of curiosity, I looked up the serial number to determine the year of manufacture. It was made in 1939, the same year as my grandpa’s tractor! Then I started to wonder how far off the date codes are. I looked at both the date code on the engine block of the H and my grandpa’s M and was shocked to find that they were the same! Both my grandpa’s M and this auction-sale H were cast at the foundry on the exact same day, August 29. We bought the H intending to resell it, but instead we’ve started a collection.

This August, we’re planning a birthday celebration for our beloved M and H. How about you? Have you ever celebrated your tractor’s birthday?

*Multiple letters were used in 1951.