Dating heavy plant and farm machinery

There is no tool on this page, and that is the finding. 337 makers of tractors, excavators, forklifts and combines were checked. One publishes a serial number decoder. Its terms forbid reproducing it, and they forbid the automated request that found it.

Every other page here ends in a box you can type a number into. This one cannot, and saying so plainly is worth more than a decoder assembled from guesswork. A machine that costs as much as a house deserves better than a tool that looks confident.

The one maker who publishes

John Deere publish a decoder for their 17-digit PIN. It names each field of the number and gives a table of year codes. It is a real, complete, maker-written scheme — the thing this whole site goes looking for.

None of it is reproduced here, and none of it will be until they say yes. Their Terms of Use reserve their content, and they are explicit about automated access: “You may not data mine, crawl or scan this Site with automated computer equipment, software or communications over the internet or any communications network.” The one scripted request that found the page was made before those terms were read. There has not been another, and the tool that reads the saved copy has no network code in it at all.

Their robots.txt does not say that. The host returns 404 for it, which under RFC 9309 means there are no crawl rules whatsoever. A file that says nothing is not a file that says yes — this site learned that from Reverb, whose terms forbade automated access while their robots.txt looked open, and it is the reason every source here is checked twice.

So the honest thing to publish is a link. Deere’s own page is where the scheme lives, it is free to read, and a person opening it in a browser gets the whole thing. A letter has been drafted; if it is answered, a decoder appears here and this section gets shorter.

Caterpillar could not be reached at all

The largest maker in the category did not answer. www.caterpillar.com timed out on every attempt.

That is recorded as unknown, not as nothing. A host that does not answer has told us precisely nothing about what it publishes, and writing “Caterpillar publish no decoder” on the strength of a timeout would be inventing a finding out of a network error. They may publish a great deal. This method did not see it.

What was checked

The pool is 337 heavy plant and agricultural machinery makers, listed in plant-makers.txt, built from Wikipedia’s agricultural machinery, construction equipment, tractor and forklift truck manufacturer categories, with websites from Wikidata’s official-website property rather than guessed at.

And read the swept figure knowing how much was there to read. Of the 156 counted as swept, 51 offered this method fewer than 25 pages to look at, and 45 of those offered nothing from a sitemap at all. A host that answers, allows us, and then has almost nothing to search still counts as swept. It is the number of doors opened, not the number of rooms searched.

Of the 53 not probed: 38 did not answer at all, 5 returned 403 on robots.txt itself, 5 block us by name, 3 went over the time limit, and 2 read fine and then refused the page.

Read the swept figure as swept, not as cleared. This method has demonstrably missed makers who do publish, on Zippo, Ludwig and Rheem. It is also blind to anything behind JavaScript, and two of the more promising pages in this family — JCB’s serial number guide and Bobcat’s — turned out to be exactly that.

Five makers asked us not to, by name

Adinotec, Fendt, HMT Limited, Hydrema and Kanga Loaders all carry Disallow: / for ClaudeBot in their robots.txt. Their sites were not read.

That is the whole of the response. There is no workaround here and no attempt at one: a request not to be crawled is honoured whether or not it is enforceable, and whether or not the thing behind it would have been useful.

Why the sweep’s hits were mostly a Danish word

Twenty-one makers returned a page whose address or text matched the search. Nearly all of them were the same false positive: “serien” is Danish, Norwegian and Swedish for “the series”, and it sits inside the word “serial” the search was looking for.

So Case IH’s Farmall-serien, New Holland’s CR-serien, Hiab’s E-serien and a dozen Konecranes press releases all came back as candidates. Every one is a product range, not a dating scheme.

Two of the real ones are worth naming because of what they are not. Toro publish a page that tells you where the serial plate is, which is useful and is not a decoder. Liebherr returned serial-number pages for their refrigerators — they make both cranes and fridges, and the sweep does not know the difference.

This is the twelfth substring fault recorded on this site, after “stamp”, updating, “serial interface”, serialization in pharmaceuticals and serial dilution in laboratories. Searching for a word inside other words is how a survey gets a plausible number that means nothing.

What to do instead

For a machine with a 17-character VIN-style number, the VIN decoder reads the year character and the check digit from the federal standard, which is public law and reproduced here in full. A great many tractors and telehandlers carry one.

For anything else, the plate on the machine and the dealer’s records are the route. That is a worse answer than a tool, and it is the true one.