Largest North American Captive Heat Treats-Tinker Air Force Base

As we work towards our 2024 list of the “15 Largest Single Location Captive Heat Treats in North America” we have another new listing, one that has not appeared on our previous lists and a very unusual one at that. Tinker Air Force Base in Oklahoma is one of the largest US Air Force bases in the USA, to give you a perspective on the size with 9,000 employees it is the largest single location employer in the state. This site at last count had 27 vacuum furnaces in various configurations which includes horizontal, bottom loading and oil quenching. Few locations anywhere in the world have this many vacuum furnaces meaning Tinker will be appearing on our upcoming list.

11 Largest Captive Heat Treats, North America – An Industry Exclusive

In 2022 “The Monty Heat Treat News” published a heat treatment industry exclusive, a list of the “10 Largest Single Location Captive Heat Treats” in North America. Since that time changes have occurred and we are now pleased to offer our 2023 list of the largest Single Location Captive Heat Treats in North America-a list which has now grown to the 11 largest. Read on to find out who are the largest captive heat treaters in North America.


Number 11 Caterpillar, East Peoria, Illinois. In years gone by we have rated Caterpillar, the world’s large construction-equipment manufacturer as one of the largest captive heat treaters in North America based on their various facilities throughout the USA many of whom have in house heat treating. Our criteria this year is slightly different in that we are looking at single location captive heat treatment facilities. However having said that we would rank the Caterpillar facility in East Peoria, Illinois as the 10 largest captive heat treat facility in North America.


Number 10 Amsted Rail – BRENCO Bearings, Petersburg, Virginia. A newcomer to our list of the 10 largest single location captive heat treaters is a bearing company, BRENCO Bearings a division of Amstead Rail, located in Petersburg, Virginia. Amsted Rail’s Brenco® Bearings was founded in 1949 to manufacture bronze journal bearings for railroad freight cars. In 1959, Brenco received conditional AAR approval for the product it is known for today throughout the worldwide railroad industry,the tapered roller bearing-in short the company makes bearings for the railroad industry. The company has locations around the world, at least two of which have in house heat treatment departments. While the heat treatment department in Petersburg is not as large as it once one it still includes multiple pit carburizing furnaces and rotary hearth units.


Number 9 Dana Corp., Queretaro, Mexico. Number 9 on our list is yet another large auto parts maker, Dana Corporation, Queretaro, Mexico. While Dana has numerous facilities around the globe that include heat treating the largest is an enormous complex in the Mexican city of Queretaro with several large, separate in house heat treating departments. There are 3 separate facilities here, Dana Forja which has a heat treating department doing annealing in continuous furnaces, Dana Cardanes which has 7 batch IQ furnaces, roughly 40 induction lines and 11 tempers and Dana, ENCO which has 2 AFC-Holcroft UBQ furnaces along with 4 pusher furnaces (as of 2020).


Number 8 Stellantis, Kokomo, Indiana. In 1956 Chrysler invested in a transmission facility in Kokomo, Indiana, a facility which now covers 3.1 million square feet (please note that there are several facilities in Kokomo, our interest is in the transmission facility). For many years now this plant which originally was called Chrysler, and subsequently FCA Kokomo before being renamed Stellantis had what was probably the largest captive heat treat in North America. At one time it included 7-Three row Holcroft Pusher Furnaces, 6-Lindberg 36 X 72 X 36 Batch IQ furnaces, 3-Holcroft single row pushers, 2- Surface rotary furnaces, 2-Seco Rotary Furnaces, 4-ECM vacuum nitriding furnaces, 30-tempering furnaces and several ECM vacuum carburizing systems. While the heat treat department is smaller than it once was it is still one of the larger in house heat treat departments in North America.


Number 7 American Axle & Manufacturing Holdings (AAM), Silao, Mexico. In 2012 auto parts supplier American Axle & Manufacturting (AAM) formally opened a new location in the city of Silao, Guanajuato, Mexico. The Silao facility was AAM’s second manufacturing facility in Mexico, joining the Guanajuato Manufacturing Complex. The opening of these facilities marked a real change in the firms philosophy as previous to this most manufacturing was in the USA including a large facility in Buffalo, New York which featured 5 single row pusher lines. Each AAM facility (including Poland) has a varied mix of heat treating equipment which includes pusher furnaces, batch IQ’s and Induction to name a few. Each of the AAM heat treating departments is very impressive, mainly because they are relatively new and obviously no expense was spared. AAAM globally can be considered one of the larger captive heat treaters in existence.


Number 6 ZF Transmission, Grey Court, South Carolina. ZF is a German company which ranks amongst the largest suppliers of automotive transmission components in the world. The location in Grey Court, SC opened in 2012 and became a hub for ZF’s work in large-scale transmission production, including eight- and nine-speed automatic transmissions. Almost exactly one year ago the company issued this press release about an expansion of the facility (an expansion which did not include more heat treating by the way), “Germany’s ZF Friedrichshafen said it will invest $200 million to build another production line at its commercial vehicle transmission plant in Gray Court, S.C. The new line is expected to begin production in 2023. More than 500 jobs will be created, the company said. The supplier on Thursday said it plans to expand production of the PowerLine, an eight-speed automatic transmission for medium-duty commercial trucks, heavy pickups and buses.” ZF is another company which made the decision to go with vacuum carburizing and the end result is that this facility has two ALD “Modultherm” systems in place with a total of 16 carburizing cells and 2 Pusher lines for annealing supplied by Ipsen.


Number 5 Linamar, Guelph, Ontario, Canada. In our fifth position we find a Canadian company, auto parts supplier Linamar. Linamar is a global company with many locations around the world doing heat treating however their largest heat treat department is in Guelph, Ontario. Roughly 15 years ago the firm made the decision to bring heat treating in house while at the same time deciding that going forward they would concentrate on batch processing as opposed to continuous. In 2022 we see that this plant now has twenty five 36” X 48” X 36” batch IQ furnaces in place combined with several vacuum nitriders and a rotary hearth furnace. Current plans include future additions to the heat treating department.


Number 4 John Deere Waterloo, Iowa. As one of the world’s largest manufacturers of agricultural machinery, heavy equipment, forestry machinery, diesel engines, drivetrains used in heavy equipment, and lawn care equipment we are sure the company needs no introduction. Their location in Waterloo, Iowa would appear to be the second largest captive heat treat in all of North America with a total of 31 furnaces (we will qualify this statement slightly by saying that 10 of these furnaces are dual chamber which we are counting as two furnaces each). The equipment comes from a variety of furnace suppliers including Surface Combustion as can be seen in this photo.


Number 3 Allison Transmission, Speedway, Indiana. In our third position we find the Allison Transmission Campus in Speedway, Indiana. This facility is the world’s largest manufacturer of fully automatic transmissions for medium- and heavy-duty commercial vehicles. Their very extensive in house heat treating department boasts the largest number of 36” X 48” X 36” batch IQ furnaces under one roof in North America-26 to be exact, just ahead of auto parts supplier Linamar in Guelph, Ontario, Canada who has 25 furnaces of the same size. In total the heat treat department at Allison includes this equipment;

  • (26) IQ Furnaces -36”x48”x36”
  • (36) Temper Furnaces
  • (6) Pit Nitride Furnaces
  • (2) Rotary Furnaces
  • (12) Induction hardeners

Number 2 GKN Driveline, Newton, North Carolina. In our second position we find another automotive parts supplier, GKN in Newton, NC. While not one of the first to invest in vacuum carburizing systems they certainly jumped on the bandwagon after vacuum carburizing proved it’s value. The company now has 39 LPC cells provided by ECM with 20 bar nitrogen quenching.


Number 1 Ford Motor Company Sharonville Transmission Facility. We are quite comfortable in suggesting that the Ford Sharonville, Ohio Transmission facility is the single largest captive heat treat facility in North America. Ford was one of the first automotive companies to embrace vacuum carburizing and the end result is that this plant now has 64 ECM LPC cells with 20 bar nitrogen gas quench systems. It is worth noting that this facility has almost 2.5 million cubic feet under roof with almost 2,000 employees;

“The Ford Motor Company Sharonville Transmission plant is a transmission manufacturing facility located in Sharonville, Ohio, United States. Established in 1958, Sharonville has long been the backup site for overflowing work at the Ford Motor Company Livonia Transmission plant. It is also where the Ford Crown Victoria’s transmission was once assembled for over three decades. With the Crown Victoria now discontinued, the Sharonville transmission plant currently overseas production of the 64140 6-speed automatic transmission – also known as the Torqshift – destined for the Ford Super Duty line of heavy duty trucks. Sharonville is where the Ford/GM 10R80 10-speed transmission is assembled. The facility also manufacturers individual gears for the 6R80, 6R140, 6F35, 6F50/55, 8F57 transmissions. These gears are then shipped to other Ford manufacturing plants like the Ford Motor Company Van Dyke Transmission plant and the Ford Motor Company Livonia Transmission plant.”

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