Thomas Register of American Manufacturers: the online alternative for finding US suppliers

What happened to the Thomas Register, with the dates

The timeline is short and every step of it is on the record.

1898. Harvey Mark Thomas publishes the first edition under the title Hardware and Kindred Trades. Over the following decades it becomes the Thomas Register of American Manufacturers, and to the people who used it daily, the Big Green Books.

Peak print era. The Register runs to 34 volumes, indexing industrial products and services from thousands of American manufacturers, alongside the Thomas Register Catalog File, which bound the manufacturers' own catalogs into the set.

2006. The 100th edition is published and is the last one printed. The regional buying guides are discontinued at the same time. The database moves fully online as Thomasnet.com, free to search.

December 8, 2021. Xometry announces the acquisition of Thomas, the company behind Thomasnet.com, in a cash and stock transaction valued at $300 million. In that announcement Thomasnet is described as carrying more than 500,000 commercial and industrial sellers and more than 1.3 million registered users, including 93 percent of Fortune 1000 companies, with more than 20 million sourcing sessions started on the site each year.

2026. Thomasnet is still free for buyers, still the deepest North American industrial directory, and now sits inside Xometry alongside an on-demand parts marketplace. If you want the full comparison of the modern platform rather than the history, that is on our Thomasnet alternatives page.

A listing was always something a manufacturer bought

There is a comfortable myth that the printed Register was neutral and that the web ruined it with advertising. It is worth correcting, because believing it will make you read results badly. The Thomas Register was funded by the manufacturers in it from the beginning. The Catalog File was literally a set of paid catalog pages, and prominence in the books followed the same logic that prominence online does now. Thomasnet today earns from supplier listings, advertising, and performance-based sponsored placement. The model did not invert when the books stopped. It just got faster and easier to buy into.

That matters for one practical reason. A supplier at the top of a results page is telling you it wants industrial buyers and has spent money saying so. It is not telling you that anyone has confirmed the company can make your part, to your tolerance, on your timeline, at a price you can carry. The certifications on a profile are claims the supplier entered, not credentials a third party has checked. Treat a strong listing as a lead worth qualifying rather than a decision already made, and you will use any directory well, in print or otherwise.

What the Big Green Books did that no successor has replaced

Ask anyone who used the Register in anger what they miss and you get the same answer: the headings. The books were built on an editorially maintained vocabulary of product and service categories, and a manufacturer was placed under the heading that described what it made. That produced something a search box structurally cannot: a finite, enumerable list. You turned to the heading, and what was printed under it was everyone. When the list ended, your search ended, and you knew it had.

Free-text search gave up that guarantee in exchange for speed. Type a description into any modern directory and you get a relevance-ranked page with no bottom, no way to tell a thin category from a complete one, and no signal about whether the right supplier was on page one, page nine, or absent because it describes its own capability in different words than you do. That is the actual regression, and it is why so many buyers still search for a directory that stopped printing twenty years ago.

An agent closes that gap from the other side. Instead of hoping your phrasing matches a supplier's self-description, you state the requirement and the constraints, and the search runs across the ways a capability gets described rather than the one way you happened to write it. The output is a bounded, ranked shortlist with reasons attached, which is the shape of answer the heading used to give you.

How to find American manufacturers now

Start by being honest about which of two jobs you have, because they need different tools. If you know the capability and want companies that have it, a directory is the right instrument and Thomasnet is the best one for North American industrial work. If you know the product and need someone to make it, a directory will hand you a list and leave the hard part with you.

For industrial parts, machining, fabrication, and MRO, Thomasnet remains the deepest domestic listing, with Xometry and Protolabs useful when you would rather upload a CAD file and get a price than build a supplier list. For consumer goods, where Thomasnet has never been strong, Maker's Row covers US factories for apparel, accessories, and home goods, and our guide to how to find a US manufacturer walks through the qualifying steps in order. If the decision genuinely turns on whether a domestic factory beats an overseas one once duty, freight, and tied-up working capital are counted, you want both sides quoting the same brief rather than two searches you compare from memory, which is the case we make in Alibaba vs Thomasnet.

Whichever route you take, the qualifying work is the same and it is yours: confirm the legal entity, check what the company actually ships, ask for references in your category, and let a sample decide. We surface the evidence and flag the risks. We do not run on-site audits or guarantee factory quality, and no directory does either.