(Editor’s note: This is the 26th installment in a monthly series highlighting some of the region’s unsung manufacturers that make products essential to the economy and, in many cases, our way of life. See previous installments here.)
Each year thousands of metal parts of all shapes and sizes arrive at S&P Heat Treating Inc., where they undergo processes crucial for them to work correctly.
“If you just form a knife out of a piece of regular steel, it won’t hold the sharpness,” said Mike Rapoza, vice president of S&P Heat Treating. “If you have a hammer that’s as soft as the nail, it’s not going to be a good hammer.”
Heat treating seems simple – heat a metal part in a furnace and then cool it off to bring out the best level of hardness. But the process is far from basic.
Each part requires its own combination of temperature and time in the furnace, which is often found through trial and error, sometimes even sending pieces back to the customer with different hardnesses to see which worked the best, Rapoza said. Though parts can also change shape and move in the furnace, customers require pieces to come back with the correct hardness within thousands of an inch of the original shape.
This makes it more important to find the right combination and treatment for each order.
“Once we find the magic, it’s locked and loaded,” Rapoza said.
There is also annealing – a heat treatment that softens metal. Some parts might also need to be a certain hardness in some areas and softer in others, which is known as selective hardening.
Each order arrives at S&P’s door with a sheet showing what the part is, the material it’s made of and the hardness the customer wants. Then the team gets to work developing the right recipe to fulfill the order, which could include a wide range of treatments from different kinds of hardening, annealing and carbonitriding.
It’s a process S&P Heat Treating has honed throughout its 38 years in business.
S&P Heat Treating was started by Arvind Patel, the company’s president who has made his way through the heat-treating ranks, including serving as chief metallurgist for the Stanley Tools Corp. in Rhode Island. In 1986 he launched S&P Heat Treating in Warwick, which relocated to its current spot on Dewey Avenue in the city eight years later.
The company has grown to serve customers worldwide, covering many industries from health care and automotive to major gun manufacturers.
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PRODUCTION LINE: Zarkpa Soe, left, part of the production team, and Andrew English, part of the shipping team, at S&P Heat Treating Inc. in Warwick handle some firearm parts that will be going into the vacuum oven.
PBN PHOTO/MICHAEL SALERNO[/caption]
Rapoza joined the business 28 years ago after meeting Patel, who lived across the street. Rapoza recalled having little knowledge of heat treating, but he was eager to learn and respected Patel as an entrepreneur.
“Arvin being an entrepreneur made no promises, except that I would grow as he grew,” Rapoza said. “As long as I was willing to put in the work and learn, he was willing to take me on, and it was a great relationship from day one.”
Metal hardening is a lot to learn on the fly, as there are many orders with different materials and specifications to keep track of. But now decades later, Rapoza has worked with every part of the heat-treating process and consults with customers on their projects.
And Rapoza is not alone, as all the current employees – except for a maintenance worker – had little experience in heat treating before coming to the company.
“It’s such a niche industry; people don’t hear about it,” Rapoza said.
At the same time, accuracy is key. Everything in heat treating is provable, as a part’s hardness can be tested in a laboratory.
“You can’t fake it,” Rapoza said. “So, we have to cross all the T’s, dot all the I’s and make sure that what we’re doing is accurate.”
S&P Heat Treating tests samples from every order to make sure they meet the customer’s needs because a metal piece’s hardness is crucial for its longevity and the user’s safety.
“If there are 50 bad pieces, that could mean 50 car accidents,” Rapoza said.
The testing is done in the company’s lab just steps away from where the parts are treated. There, a part is cut in half and placed in a specially made epoxy mount. Then the piece goes under a microscope that also makes a diamond-shaped indent. The scope is connected to computer software, which shows the hardness of the piece at different depths.
Originally, S&P Heat Treating sent samples out to a separate laboratory for testing, but it would take two to three weeks to get the results – far too long for the company’s customers who wanted pieces ready within days.
Then in 2015, the company doubled its facility space – going from 3,000 to 6,000 square feet – by taking up two buildings across the street from the original facility. One of the buildings housed a metallurgical laboratory, which allowed S&P to run its own tests in just a day. And the other included an oxide line and three more vacuum furnaces, which get rid of any contaminants.
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SAMPLE PIECE: James Gould, a member of the quality assurance team at S&P Heat Treating Inc., holds one of the medical instruments
going into the vacuum oven.
PBN PHOTOS/MICHAEL SALERNO[/caption]
Before then, S&P Heat Treating had added a new internal quench furnace and another vacuum furnace in 2008. And these furnaces almost never shut off.
If the furnaces are turned on and off too much, the repeated change in temperature could cause bricks inside to crack and fall, Rapoza said. But if a furnace is down, that could cause weeks or months of delays – time customers don’t have.
“You can’t have a piece of equipment down for 16 weeks. Your customer will not deal with that,” Rapoza said.
A major focus of the business is preventative maintenance, and every six months, the furnaces are shut down in a staggered pattern so maintenance workers can examine them. The company also has outside vendors assess the furnaces to make sure they are working properly and let them know if there’s anything that needs to be fixed.
Having the ovens running all day also means employees work around the clock. Rapoza even recalled times he came to work at 1 in the morning because a batch was ready to come out of the oven.
While the hours can be long, S&P Heat Treating has a low turnover rate – with the newest worker starting three years ago – as the 12 employees see each other as family.
“Monday morning, people come in and know what they have to do,” Rapoza said. “There’s never any bickering.”
