#52 Vacu Braze, Quakertown, PA

A new entry on our list of “The 50 Largest North American Commercial Heat Treaters” is “Vacu Braze” of Quakertown, PA. The company offers “high end” heat treating for industries such as medical, aerospace and defense and operates out of a modern 40,000 square foot facility. The firm was founded by Mr. Ralph Puerta and interestingly enough his son Doug is President of another company on our list, Stack Metallurgical in Portland, Oregon.

#51 Akron Steel Treating, Akron, Ohio

“Facts and Figures on AST – 82 Years in Business – 20 Years NADCAP Accredited – 38 Employees – 65,000 SqFt Facility – Heat Treating in Salt, Controlled Atmosphere, Air and Vacuum.

#50 Ohio Metallurgical Service, Inc., Elyria, Ohio

A new entry this year on our list of “The 50 Largest Commercial Heat Treaters in North America” is “Ohio Metallurgical Service, Inc.”, of Elyria, Ohio. Founded way back in 1947 the company has always been privately owned-as far as we know by the Gaydosh family with John Gaydosh the longstanding President. The firm is “Nadcap” accredited and offers a variety of processes including carburizing, vacuum hardening and induction hardening.

#49 Lone Star Heat Treating, Houston, Texas

Founded in 1945 “Lone Star Heat Treating” is one of the older commercial heat treats in the USA. As far as we know the company has always been owned and run by the Van Dorfy family, the current President is Mike Van Dorfy, Jr. Like all heat treaters in Texas, Lone Star’s business is based upon the oil and gas industries although the company has diversified to some extent over the years. Lone Star offers induction hardening, atmosphere carburizing, deep hole drilling and vertical heat treating.

#48 Engineered Heat Treat-Subsidiary of BMT Aerospace

In 2024 we added “Engineered Heat Treat” of Madison Heights, Michigan to our list of “The 50 Largest Commercial Heat Treaters in North America”. “Founded in 1959, Engineered Heat Treat, LLC provides a variety of heat treat services to the Aircraft, Agriculture, Automotive, Earth-moving equipment, High Performance Racing, Military, and Tooling Industries. As a Nadcap & AS9100 approved company, Engineered Heat Treat’s foundation for quality is coupled with rigorous controls in place for maximum customer confidence and satisfaction.”

#47 Lark Heat Treating

“Lark Heat Treating” was founded in 1978 by brother’s Frank and Gene Clark with the guidance and inspiration of their father, Wade Clark, whose heat treating career started in 1936. Now owned and operated by Frank and Gene, Lark Heat Treating is one of the top commercial heat treaters in the southern United States. Lark operates out of a 55,000 square foot facility and can be classified as a “full service provider” in that they offer most commercially available processes, carburizing, nitriding, vacuum hardening, induction and a few others.

#46 Winston Heat Treating Inc., Dayton, Ohio

In 1959 “Winston Heat Treating Inc.”, was formed to service the local tool & die market. Since then the company has always focused on moving forward with new technologies and in the 1970’s the firm became a real pioneer in vacuum hear treating which resulted in Winston becoming one of the first to achieve both ISO and NADCAP status. Like so many on this list this is a family owned business with David Reger acting as President. We have watched Winston grow and invest and it is a fine example of a modern commercial heat treater.

#45 Southwest Metal Treating Corp., Fort Worth, Texas

“Southwest Metal Treating Corp., (SWMT)”  is a family owned commercial heat treater in business for over 40 years run by Mr. Ryan Fussell. The company is full service in that it offers most heat treating processes including but not limited to; vacuum heat treating, carburizing, nitro carburizing, flame hardening, normalizing, stress relieving and Plasma Nitriding. The company operates out of a 50,000 square foot facility located on 7 acres.

#44 Voestalpine AG

“Voestalpine AG” is an Austrian steel-based technology and capital goods group based in Linz, Austria. With over 30 locations around the world offering heat treating the company would rank as one of the larger commercial heat treaters in the world. While their heat treating operations in North America are relatively modest compared with their global footprint they do operate two very impressive facilities in North America, one in Canada and one in Mexico with additional capacity in Texas. Their heat treat operations are both captive heat treating of their own products and commercial heat treating. This photo shows their Canadian facility. 

#43 Peters Heat Treating

Located in Meadville, PA, USA family owned “Peters Heat Treating” has thrived over the years, so much so that the company now has 2 locations and roughly 85 employees. “Peters” can be considered a “one stop shop” in that there are few if any processes that the company doesn’t offer. We are pleased to see them on our list of the “50 Largest Commercial Heat Treaters in North America”.

#42 Applied Thermal Technologies

“Applied Thermal Technologies” in Warsaw, Indiana, USA is almost entirely a “vacuum” shop. This is a company which has come a long way since its founding in 1992 by Micky Bradican (current owner) and two former partners. The company now has a total of 3 buildings in one location and services a number of industries although medical and aerospace feature very prominently. 

#41 Phoenix Heat Treating, Phoenix, Arizona

Phoenix Heat Treating, Phoenix, Arizona, USA; Phoenix Heat Treating has been family owned and operated since 1963. With 75 employees operating 24/7, Phoenix Heat Treating primarily services the Aerospace and Defense markets, but Energy and Semiconductor are close behind. Not to mention general manufacturing, tool & die, and firearms. Phoenix Heat Treating is proud of its paperless quality system and merit Nadcap status. On a practical note, Phoenix Heat Treating has over 14,000 unique part number processes saved and operates 60+ thermal units. Of course, Phoenix Heat Treating performs conventional heat treating process in IQs and Vacuums, but it is the more unique processes that make Phoenix Heat Treating stand out. Processes such as, boiling water aluminum solution treating, high temperature thermal oxidations, aluminum up-hill quenching, aluminum thermal cycling, mar-quench, austempering,  and titanium solutions. Phoenix Heat Treating is the diamond in the desert focused on becoming the most customer centric heat treater in the county.

#40 Specialty Heat Treating, Houston, Texas

“Specialty Heat Treat, Inc.” is a family owned commercial heat treater founded in 1993 by Tom Moore in Houston, TX. SHT operates a 100,000 square foot facility on 9 acres and has grown to 42 furnaces up to 25’ in length. Like all heat treaters in Texas the company’s fortunes are closely tied to the oil and gas industries. In 2024 Gord and Dale Montgomery of “The Monty Heat Treat News” had the opportunity to tour this facility at the invitation of Sam Moore, President-the story can be found here; https://themonty.com/heat-treating-in-texas-is-different-specialty-heat-treat/

#39 Pacific Metallurgical, Kent, Washington

The US Northwest is not a substantial area for commercial heat treating but there are several companies in the area that stand out and “Pacific Metallurgical” in Kent, Washington is one.  Founded in 1968 the firm covers many of the bases when it comes to processes offered-carburizing, gas nitriding, stress relieving, press quenching, neutral hardening and a substantial vacuum hardening department consisting of 3 GM 48x48x90 furnaces as well as two Ipsen 924s.  The main focus of the company is the aerospace industry. 

#38 Modern Heat Treat, Richland Hills, Texas

“Modern Heat Treat” The company was founded in July of 2009 by Brad Luce and Rudy Saucedo (unfortunately Brad passed away in 2019 at a very young age, Rudy is now President and owner). What started as a relatively small operation featuring several batch IQ furnaces has grown into a very substantial company which includes numerous batch IQ furnaces, vacuum furnaces, induction equipment, flame hardening, deep freeze and straitening capabilities.

#37 Texas Heat Treating

Everything is bigger in Texas and that includes heat treating. “Texas Heat Treating” is one of several commercial heat treaters in the state to make our list and like most of the others the focus is on servicing the oil and gas industries. CEO C.H. “Buddy” Crossley started Texas Heat Treating in 1977 as a small company in a 6,000 square foot shop. Today, the company has expanded to two large facilities, the first in Round Rock, Texas, and the newest plant in Fort Worth, Texas. It is run by Buster Crossley and features batch heat treating equipment including IQ’s, pit furnaces, vacuum furnaces and nitriding systems.

#36 Byron Products, Fairfield, Ohio

Founded in 1982 by Mark Byron in a 1 car garage, “Byron Products”has grown into a very significant player in the US Midwest commercial heat-treating region.   The NADCAP approved company offers brazing, heat treating, welding and coatings all with a strong emphasis on the aerospace industry. Byron excels in the heat treating of stainless steel and high temperature aerospace alloys. The company operates out of a facility in Fairfield, Ohio. 

#35 Accurate Steel Treating, Southgate, CA

For our 35th largest North American commercial heat treater we move to California to look at “Accurate Steel Treating” who bill themselves as “The Fastest Growing Aerospace Heat Treating Company in the West”. “Accurate Steel Treating was founded in 1962 on a strong commitment to quality and customer service. In 1989, Accurate Steel Treating was acquired by a new management team and embarked on a carefully planned expansion program. During the next 25 years, new processes and equipment were added to keep pace with growing demand including high-pressure gas quench vacuum heat-treating, precision carburizing, and ion nitriding. In 2012, management decided, along with encouragement from several key customers, to enter the Aerospace market to be better diversified and capitalize on the many opportunities developing in this sector.

#34 FPM Heat Treating

Founded in 1979 “FPM Heat Treating”has two locations in the US Midwest, Elk Grove Village, IL and Cherry Valley IL. FPM has the capability to offer most heat treating processes including Through hardening, Carburizing, Carbonitriding, FNC and Nitriding, from a variety of furnaces including batch IQ furnaces, mesh belt, vacuum and salt bath. The company has NADCAP approval along with CQI-9.

#33 Tube Bending Technology

This is the first time “Tube Bending Technology” has made our list of the “50  Largest North American Commercial Heat Treaters” and it did it through two acquisitions in 2024. The California based company is a manufacturer and fabricator of tubing and ducting assemblies who has always sent a great deal of heat treating out to local providers of brazing and heat treating services. The firm made the decision that it wanted all parts of the manufacturing process to be under their direct control and the end result was that it acquired two local heat treaters, “Thermal Vac” in Orange, CA and “Scarrott Metallurgical” in Los Angeles, CA. 

#32 Sun Steel Treating

“Sun Steel Treating”in Michigan is best known as one of the largest commercial plasma nitriding firms in North America; “Since 1958, Sun Steel Treating has specialized in providing our customers exceptional quality, expertise, and timeliness. Whether it’s hardening alloys, carbon steels, tool steels or high speed specialty steels, our engineers know the precise metallurgical processes to apply. In 1981, Sun Steel Treating pioneered the use of plasma Nitriding as a viable surface hardening treatment.”   Sun Steel is privately owned by Mr. Jim McGuirk and operates out of large facility close to Detroit, Michigan. The company concentrates on two areas, vacuum heat treating and Plasma Nitriding.

#31 Metex Heat Treating, Mississauga, Canada

“Metex Heat Treating”While there are few heat treat processes the company doesn’t offer, Metex is best known for their mesh belt heat treating of fasteners. Metex operates several continuous furnaces including 3 of the largest in Canada-each with a capacity of 6,000 pounds per hour meaning they can process over 300,000 pounds per day. In 2024 the company acquired another Canadian commercial heat treater Exactatherm also in Mississauga which expanded the number of heat treat processes the company offers. 

#30 Pinson Valley Heat Treating, Alabama

Pinson Valley is owned and run by the Hendry family and is now in its third generation. Founded in 1970 the company has a very unique mix of capabilities including vacuum heat treating, atmosphere and some very interesting and unique tip up style furnaces.

#29 Thermetco, Quebec, Canada

Founded in 1982 “Thermetco” is a privately held company with 3 locations in Quebec; the main plant in Châteauguay (near Montreal), a smaller heat treat facility in Granby, Quebec and a third NDT location in Montreal. In terms of processes offered there are few that the company doesn’t offer in that they have vacuum hardening (3 furnaces at the main location with one have a diffusion pump), 4 batch IQ units offering carburizing and neutral hardening, salt processing, stress relieving, and annealing to name a few all operating 24/7. The company is Nadcap certified and in the summer of 2025, they will be an approved supplier to aerospace company “Safran Landing Gear Systems”.

#28 ALD Thermal Treatment Inc.

“ALD Thermal Treatment Inc.” is part of “ALD” in Germany and it’s commercial heat treating operations include two facilities in North America; ALD Thermal Treatment, Inc., in Port Huron, MI, and its sister plant in Ramos Arizpe, Mexico, a state-of-the-art facility in Saxony, Germany, and a location in Suzhou China. All of the plants focus on Low Pressure Carburizing (LPC) and High-Pressure Gas Quenching (HPGQ). For the purposes of this report, we only considered the US and Mexico plants. Originally, they were 100% automotive related however over the years they have diversified to some extent. Both North American facilities are extremely impressive to visit. 

#27 Q-Tech, Heat Treat LLC.,  DFW, Texas

“Q–Tech Heat Treat LLC.” located in Dallas, Texas was founded in 1972 by R.D. Fussell and sons in a 1,000 sq foot building with 2 furnaces. “We have grown to our current size of 100,000 sq feet and over 40 furnaces. Our main focus is on customer needs, and servicing them on a personal level. We have been ISO 9001:2015 approved since 2003.” Q–Tech remains a family owned business to this day with Sean Fussell as President which marks the third generation. It is interesting to note that the Fussell family is one of the largest names in the commercial heat treat industry in Texas, as an example Ryan Fussell is the owner of “Southwest Metal Treating” which also makes our list. 

#26 Century Sun Metal Treating, Traverse City, Michigan

You would not expect to find one of the largest commercial heat treaters in North America in Northern Michigan, however such is the case with “Century Sun Metal Treating” which for over 30 years have been offering heat treating services in Traverse City, Michigan. Century Sun has a great deal of vacuum and plasma nitriding capacity which they use to service a wide variety of industries. In 2021 the company was acquired by Hillcrest Investment Partners, LLC, a private investment group.

#25 Continental Heat Treating Santa Fe

Nadcap approved “Continental Heat Treating”is an aerospace approved heat treating company located in Santa Fe Springs, California. Established in 1957 in Downey, CA the company moved to their current location in Santa Fe Springs in 1969 where it has grown and prospered under the leadership of Mr. Jim Stull.

#24 East Carolina Metal Treating & Virginia Metal Treating

Family owned “East Carolina Metal Treating” was founded in 1976 and over the years has grown into two locations; a 45,000 square foot facility just outside of Raleigh, NC and a second location (Virginia Metal Treating) in a 20,000 square foot building in Lynchburg, VA. ECMT offers a full range of heat-treating services including Vacuum, Batch IQ, Nitriding/FNC, Induction, Cryogenics, Salt bath hardening with austempering and marquenching, Stress Relieving, Age Hardening, as well as Black Oxide. 

#23 Kittyhawk

“Kittyhawk” was a new entry for us on our 2023 list at which point “The Monty” ranked them at #32. However March 7, 2024  it was announced that Kittyhawk, Inc.  backed by their parent company Dallas-based private equity firm Trive Capital had acquired Stack HIP, LLC (“Stack HIP”) from Stack Metallurgical Group. This acquisition increased their sales to over $20 million USD and “The Monty” is putting the company in the 23 spot for 2025.

#22 Rex Heat Treat

“Rex Heat Treat” is a family owned-and-operated business that entered business in 1938 in Pennsylvania making it one of the oldest commercial heat treats in North America. The company has two locations in PA offering a total of 30 heat treating processes which covers industries as diverse as Mining and Drilling, Energy, Aerospace and Defense, and Transportation. The company claims to have the world’s largest vertical vacuum oil quenching furnace. 

#21 Vac Aero, International, Burlington, Canada

​“Vac Aero International”  is the largest commercial heat treater in Canada and makes our list in the 21st position this year. The firm has several locations in Canada offering commercial heat treating, coatings and new vacuum furnaces. Its commercial heat-treating division is almost entirely aerospace related with a strong empasis on processing landing gear which means the company is NADCAP accredited. Under relatively new management we are seeing substantial growth in both their heat-treating division and in their furnace manufacturing division-expect to hear more about the company in the near future. 

#20 Flame Metals Processing Corp., Rogers, MN

Privately owned “Flame Metals Processing Corp.”  (Dennis Stevermer) was founded in 1985 and operates out of a 102,000 square foot facility with over 100 employees working 7 days a week in the Minneapolis/St. Paul metropolitan area. Focus is on the General Industrial Markets-Off Highway, Construction, Marine, Outdoor Recreational, Agricultural, Mining and Wind Energy. With eleven integral quench furnaces (9000 lb. max capacity) and two pit furnaces (25,000 lb. capacity), the company is best known for its ability to process large critical components. Additional capabilities include continuous processing, vacuum, salt bath nitriding, neutral salt, induction, aluminum and car bottom.”

#19 Pressure Technologies Inc.

“Pressure Technology Inc. (PTI)“. Do companies doing strictly Hot Isostatic Pressing (HIP) deserve to be on our list of the largest commercial heat treaters in North America? In our opinion yes as “Hiping” is clearly a form of heat treating (although not one that most people think of).  “Pressure Technology is a leading provider of high quality hot isostatic pressing (HIP) to the aerospace, medical, ceramics, electronics, precision casting, powder metallurgy, additive manufacturing and a variety of other industries.” 

#18 Industrial Steel Treating,  Jackson, Michigan

“Industrial Steel Treating Company” (IST) began operations in Jackson, Michigan in 1943, initially servicing the growing tool and die industry in mid-Michigan, Ohio and Indiana. This is one of the largest single location heat treaters in the US operating out of an enormous 350,000 square foot facility and is owned and run by the “Levy” Family. “Two separate, across-the-street facilities house production, prototype samples and warehouse-inventory management capabilities. IST offers gas nitriding, carbonitriding, induction hardening and several other processes. The firm is now fourth generation which few commercial heat treaters can boast of”. 

#17 Thermal Process Holdings

“THERMAL PROCESS HOLDINGS” in the US Midwest consists of several different locations united under one banner over the past few years. The website is rather out of date in that it does not mention Rockford Heat Treaters acquired several years ago and also mentions Diamond Heat Treat in the Chicago area which is either closed down now or will shortly be. Ownership is a venture capital firm in the US Northeast. 

#16 Hansen Balk Steel Treating Company, Grand Rapids, Michigan

We are going to rely on “Hansen Balk” to summarize the company, we will add that the company is privately owned and is one of the largest vacuum heat treaters in North America. “Since 1955, Hansen/Balk in Grand Rapids, Michigan, USA has built a reputation as a state-of-the-art provider of steel heat-treating services. Our 85,000-square-foot facility features a full cohort of best-in-class batch vacuum and batch atmosphere furnaces, capable of processing orders of all sizes. We offer a variety of services, but are best known for the breadth and depth of our vacuum heat-treating capabilities-including high-pressure quenching up to 15 Bar-as well as unique services such as cryogenic treating, flame hardening and induction heat-treating services. We adhere to the most technologically advanced heat-treating methods with modern equipment to ensure your parts meet the required specifications-from hardness tolerance to surface finishes. We also bring customers a deep well of metallurgical knowledge, formed over six decades of work on millions of parts.”

#15 Specialty Steel Treating

Specialty Steel Treating, founded 1956, has been performing precision heat treating for more than 60 years. The privately held company has 4 locations in the US, three in the Detroit, Michigan area and one in Connecticut. While Specialty is located in the auto capital of the world it has broadened its customer base over the years and now has a very strong presence in the aerospace and bearing industries. https://www.sst.net/

#14 Heat Treating Services

Based in Pontiac, Michigan HTS is a privately owned commercial heat treater founded in 1978. Being in Michigan the company is heavily involved in the auto industry and the Hynes family have done a tremendous job of guiding the company through the ups and downs of the last few years. HTS has 4 plants in Michigan and serves the ferrous metal industries with thermal process and clean capabilities, which exceed sixty-four (64) million pounds per month. In total HTS had over 200,000 square feet under roof and 250 employees. On a side note, Jeff Hynes of used furnace business “Furnaces, Ovens & Baths” is a cousin of the owners proving the heat treat industry is a very close one.  Heat Treating Services | Home (htsmi.com)

#13 Nitrex

Nitrex consists of three divisions, Nitrex Turnkey Systems, United Process Controls and Heat-Treating Services-our focus is on their heat-treating services in North America. The firm has 4 locations in North America; Franklin, Indiana, Aurora, Illinois, Mason, Michigan and Querétaro, Mexico. While Nitrex is best known for their nitriding services their heat treat facilities offer most processes including LPC. Recently the company installed what is believed to be the largest pit nitreder in North America, a picture of which can be seen here.  https://www.nitrex.com/en/

#12 Stack Metallurgical

​In the US Northwest privately owned Stack Metallurgical is  the largest commercial heat treater by a large margin; Stack Metallurgical Group consists of three sites strategically located throughout the Pacific Northwest.  Stack specializes in advanced heat treating, aluminum anodizing and painting, and hot isostatic press (HIP) services. With a rich history dating back to 1946, Stack has become a trusted partner to demanding clients in industries such as aerospace, power generation, precision cutlery, oil and gas, and general industrial.  Stack has been privately held by the Ederer family since 1974.  Over the last 46 years, the business has grown and expanded into new markets. About Us – Stack Metallurgical Group

#11 Dowa Thermotech

Globally Japan based Dowa Thermotech is one of the largest commercial heat treaters in the world so it is no surprise that it also ranks as one of the largest in North America. Their facilities in San Luis Potosi, Mexico and Bowling Green, Ohio are both dedicated to servicing the Japanese automakers which means that they largely “fly under the radar” and don’t usually appear on lists of commercial heat treaters. The company almost exclusively uses furnace built in Japan and their focus is very narrow-the automotive industry. Locations (Overseas) | DOWA Thermotech Co., Ltd.

#10 ThermTech

We would consider, ThermTech in Waukesha, Wisconsin, USA to be the dominant commercial heat treater in their area; “ThermTech in Waukesha, Wisconsin is a privately held commercial heat-treating company that offers a wide range of services to a diverse and discerning set of customers. It was founded in 1982 by Charles Wiberg and remains a family owned business under the guidance of Mary Springer and her brother Steve Wiberg. We would consider ThermTech to be a full service shop in that it offers most commercially available heat treat processes.  Metal Heat Treating and Metal Finishing – ThermTech

#9 Ajax Metal Processing 

“Ajax Metal Processing” makes our list of the 50 (+2) Largest North American Heat Treaters for the first time ever, mainly because they do not fit the typical model of a commercial heat treater. Based in Detroit, Michigan it is supposedly the largest North American provider of raw material wire, heat treating (annealing), plating, locking and sealing services. They process over 300 million pounds of material per year and have numerous Can Eng mesh belt furnaces. By any standard this is a very large commercial heat treater even if they differ from many of the others on our list.  

#8 Parker Trutec

“Parker Trutec” is a North American subsidiary of Japan based Nihon Parkerizing, a very substantial player in the global heat treat industry. In North America Parker has 4 heat treat locations in Ohio, Tennessee, Arkansas and Mexico. The Springfield, Ohio facility is fairly typical of the plants and has this equipment;

• Salt Bath Nitriding Furnaces (FNC) processing our Isonite process to AMS 2755 (High Cyanide Salt).
• Salt Bath Nitriding Furnaces (FNC) processing our Isonite QPQ process to AMS 2753 (Low Cyanide Salt).
• Salt Bath Nitriding Furnaces (FNC) processing our Isonite LiFe process.
• Gas Ferritic Carburizing Furnaces (FNC) processing to AMS 2757.
• Batch Carburizing with Dowa, Surface Combustion and AFC-Holcroft Furnaces.
  • Carburizing, Carbonitriding, Neutral Hardening (Quench & Temper), Normalizing.
• Continuous Roller-Hearth Carburizing Furnaces (Dowa).
• Vacuum Degreasing Systems for pre- and post-carburizing.
• Hanging and barrel shotblasters.
• Vibratory polishing equipment.

#6 Braddock Metallurgical

In 6^th position we have a family-owned business, “Braddock Metallurgical”which was founded in 1953 by William Braddock. The company has eight production facilities mainly in the US Southeast; however they also have plants in NJ and Puerto Rico. Certainly, in the growing US Southeast region Braddock is the dominant commercial heat treater. The company is a full-service heat treater in that they offer virtually every process available. We are quite confident in saying that they are the third largest family-owned commercial heat treater in North America. 

#5 Bluewater Thermal Solutions

“Bluewater Thermal Solutions” operates 9 different heat treat and brazing facilities around the USA. The company offers different heat-treating processes throughout their facilities depending upon the geographic area. For instance, the Ridgway, PA location (located in the heard of the powdered metal industry) offers different processes than say the facility in Houston, Texas. Bluewater is very strong in brazing and also in the boronizing process. The company is owned by private venture firm Aterian Partners in New York.

#4 Woodworth Inc. 

The fourth largest North American commercial heat treater on our list, “Woodworth Inc.” is a privately owned company which operates 4 facilities in two countries and specializes in large volume automotive work. “Woodworth Inc. provides a wide range of heat treatment services through our four facilities. We are currently located in Pontiac, Homer, and Flint, Michigan, as well as Puebla, Mexico. The company operates 40 large furnaces in North America. Woodworth Inc. has installed capacity to run 16 million + rotors per year. (2.2 million Lbs / Day).” Woodworth is similar to many heat treaters on our list in that they are almost exclusively dedicated to the automotive industry, albeit on a very large scale.

#3 Solar Atmospheres

With recent changes to our “Top 50” listings “Solar Atmospheres” now becomes the largest privately owned commercial heat treaters in North America. “Solar Atmospheres” has 6 locations around the USA offering commercial heat treating (mainly vacuum) and two other locations related to vacuum furnace manufacturing which go under the name “Solar Manufacturing” (we should point out that Solar Manufacturing is one of the largest vacuum furnace builders in North America).

#2 Aalberts Surface Technologies

Based in the Netherlands “Aalberts Surface Technologies” is one of only two companies on our list which has a substantial global prescence being very strong in both Europe and North America. Since the company entered the North American market a number of years ago, they have seen spectacular growth largely through acquisitions such as Premier Thermal, Applied Process, Alfe and several others. December 27, 2024 it was announced that Aalberts was acquiring Paulo, the largest privately held commercial heat treater in North America (at that time).

#1 Bodycote

Based in the UK we have ranked “Bodycote” as the largest North American commercial heat treater and indeed the largest globally for a number of years now.