52 Largest North American Commercial Heat Treaters -“Tohken Thermo”

Each year “The Monty Heat Treat News” offers a heat treat industry exclusive, a list of the 52 largest North American commercial heat treaters as ranked by annual sales (the 2025 list can be found at “52 Largest North American Commercial Heat Treaters 2025″). 

One of the things that makes this list so interesting is that it is constantly in a state of “flux”-each year brings changes. For example family owned “Paulo” was for years ranked in the second or third spot, with their acquisition by “Aalberts Surface Technologies” they disappeared from our list. “American Steel Treating” in Perrysburg, Ohio was a staple on our list for years, unfortunately this facility closed a year ago.

Our 2026 list will reflect a changing industry with at least one new addition, “Tohken Thermo Mexicana de SA de CV” in Aguascalientes, Mexico. “Tohken Thermo” will be included on our list this year not because they suddenly saw an enormous spike in sales but because (much to our chagrin) we were not aware of how large the company was until “Tohken Thermo” approached us directly with detailed information about the company.

“Tohken Thermo Mexico” is part of “Tohken Thermo”, the largest heat treating group in Japan. Like many of the Japanese commercial heat treat locations in North America it is entirely dedicated to Japanese auto component facilities.

This is how “Tohken Thermo Mexico” describes this location and their processes; “The Heat Treatment service we offer is the best in the world, the type of services we offer are nitriding furnaces as well as the carbonitriding, quenching and tempering type. We also have the necessary technology to provide any type of thermal treatment they require, as well as the necessary experience to respond at all times to the needs of our most demanding customers”.

We won’t keep you in suspense, this location has over 250 employees with annual sales of approximately $17 million USD which will guarantee them a spot on our upcoming list of “52 Largest North American Commercial Heat Treaters 2026.