The Differences Between Automotive & Aerospace Heat Treating-Mr. Raman Bawa
Mr. Raman Bawa is President of commercial heat treater Metex Heat Treating in Brampton, Ontario, Canada one of North America’s largest commercial heat treaters and a company which focuses strongly on large volume automotive work.
In 2024 the company acquired another local commercial heat treater by the name of “Exactatherm”, a facility which focuses on aerospace heat treating.
During a recent meeting between Jordan Montgomery of “The Monty Heat Treat News” and Raman the conversation shifted to the differences between automotive heat treating and aerospace heat treating. Raman’s comments were so concise and “down to earth” that we asked if he would be willing to put them into writing-this is the result;
Jordan Montgomery: It has now been almost 3 years since you acquired “Exactatherm” and consequently entered the aerospace heat treat market. Is there a substantial difference between the two or is heating metal the same whether it is an auto part or a plane part?
Raman Bawa: The principles are the same, but our approach is quite different. At Exactatherm, we run our equipment gently to keep it running tight and keep temperature uniformity stable and robust. We use generous ramp rates that let the furnace come up to temperature slowly, and we often have long gaps between loads. It may be inefficient, but the tolerances in aerospace demand that the equipment run extremely well.
At Metex, our equipment still meets the strict standards of CQI-9, but we run it much harder and make sure we minimize any lost time between loads. That’s a must to meet the volumes and pricing automotive requires.
Jordan Montgomery: For the auto industry you need CQI-9 certifications amongst others, for the aerospace industry it is of course Nadcap-how different are the two systems? This of course leads to the obvious question-which do you prefer?
Raman Bawa: The CQI-9 requirements, while sometimes challenging, are practical and important for building a system where high-volume heat treatment can succeed. It casts a wide net across the QMS to capture the key areas required in heat treatment. With high-volume automotive work, we’re only sampling our treated product to confirm it meets spec — that kind of volume needs very strong system controls to ensure every piece is treated correctly without checking every single one.
Nadcap is deep and prescriptive on the physics of the process — it gives detailed requirements on how orders are received and stored, equipment capabilities, the conditions that must be met before processing, and in-process controls. It’s extensive across the board.
I’ll take the diplomatic answer here and say both are strong in their respective areas. CQI-9 is well suited to automotive, where we deal in pounds, not pieces — it strikes the right balance for a high-volume production environment. Nadcap’s intricate requirements, covering every area, matter when you consider the specialized nature of the industry.
Jordan Montgomery: Metex is use to eye watering volumes, for instance your website claims 80 million pounds of parts processed per year. I would have to assume that your aerospace work is measured in 10’s of thousands of parts per year. How do you get your head around these radically different volumes?
Raman Bawa: It took a while to adjust. We run roughly 300,000 lbs a day at Metex, and at that volume the pace has always been go, go, go. Most of our jobs are awarded to our customers first and then flow to us, so once we’ve gone through our approval process, we’re confident a certain volume of that part number will keep coming. That let us make every system highly efficient — order entry is streamlined, our loading process and recipes are set, and our quality checks are streamlined. We can get 20,000 lbs in from a customer in the morning and return it that afternoon, every day of the week, and our systems are built to run that accurately and consistently.
In aerospace, our customers are often medium to small machine shops. We hold approvals for many parts across a number of aircraft, but the frequency we receive those parts varies a lot, and our customers themselves often don’t have great insight into when parts will actually reach us for heat treatment. We tried building the same kind of system at Exactatherm, but the variability in when parts actually arrive made that tough to streamline. A good example is fixturing: we have a vacuum oil quench furnace that can run up to 3,000 lbs — think of it as analogous to a batch IQ. Some aerospace parts come in every month, and our furnace could fit at least three months of that production in a single load, but our customer has no way of making that many parts at once, and I don’t think the release system in aerospace could even tell us how many parts will need to be made at a given time.
Jordan Montgomery: Metex has always had batch IQ furnaces, mesh belt furnaces and induction systems whereas “Exactatherm” is generally vacuum furnaces. Did you have to fundamentally change your thinking about the different technologies and volumes? For instance, how does this effect part flow? Training for operators? Data logging systems?
Raman Bawa: With most of my experience in atmosphere furnaces, learning vacuum has been an interesting challenge. They’re simpler machines with far fewer moving parts, and since they ramp down in temperature after each load, it’s much easier to see inside. The control systems were more of a challenge — understanding the different interlocks and safeties took time. We’ve been fortunate that both companies have long-tenured employees who’ve been able to train the new people coming in.
Data logging, on the other hand, has been the same across both systems. At Metex, we’ve always strived for the most sophisticated logging and digital control systems we could get, and Exactatherm and aerospace demand exactly the same thing.
Where we do see a real difference is part flow — specifically, our ability to run the furnace back to back. With vacuum, we have to cool the furnace down before we can bring the next load in. With our atmospheric furnaces, we never ramp down — it’s one load after another. That’s a big part of why our throughput is so much higher on the atmosphere side.
Overall, given the volumes we’re processing in aerospace, when we look at new equipment, we’re looking at whether it increases our service offering — a new process, or a new prime approval we didn’t have before. With the volumes and unpredictability from our customers, the ROI has been hard to predict and with that our philosophy has had to change to “build and they will come” vs automotive where we are constantly trying to keep up with capacity forecasts and how many more furnaces do we need to add to fulfill our 2027 and 2028 promises.
Jordan Montgomery: What about profitability? Automotive heat treating is renown for laser thing margins where aerospace heat treating is considered “higher margin” work. Is this a fair statement? If so I would have to assume that the smaller volumes in aerospace are compensated by a higher margin.
Raman Bawa: Definitely. The smaller volumes are often subject to higher minimum charges, plus a premium for the Nadcap system itself. The paperwork and traceability requirements need dedicated staff to make sure the Nadcap process is followed exactly before, during, and after we run the job.
Jordan Montgomery: Now this is probably an unfair question; after many years of experience with large volume heat treating and now a couple of years of aerospace experience do you have a preference of one over the other? Can you see your direction changing either to more vacuum work or more atmosphere?
Raman Bawa: I do like both, but for different reasons. The automotive side is exciting because the parts we process end up in nearly every vehicle on the road today, and a lot of what we run is safety-critical — seats, doors, brakes. There’s real pride in knowing our work matters, and in our commitment to quality for that sector. The vacuum and specialized side is fascinating in a different way: the materials are exotic and expensive, and sometimes you can’t even fathom the end use. I remember processing parts that were going onto a rocket headed into space, and you find yourself thinking about how many people it took to get that rocket ready, and how your small piece of the process became part of something so much larger. They’re both great, each in their own way.
In automotive, we do a lot of fasteners, stampings, and cold-headed products focused on the structure of the vehicle. The materials in these parts have stayed consistent for years and are made to run in atmospheric furnaces — they don’t change from year to year, or with changes in transmission. I don’t foresee big changes here. There’s always talk of LPC being broadly introduced into the auto sector, but in our experience it’s been done almost exclusively in-house by the OEMs themselves. With automotive’s razor-thin margins, I think moving to higher-priced alloys that need vacuum processing would only make sense for a very specialized part of the vehicle — doing it broadly would drive up the cost of every part.
Aerospace uses highly specialized materials that demand vacuum furnaces. I can’t see that industry ever moving toward a cheaper material that could run in an atmospheric furnace.
