Travelers taking Interstate 78 through Upper Macungie Township may get a quick glance at the industrial building housing Precision Roll Grinders. What they may not know is that for more than 50 years, the company has been providing an essential service to thousands of manufacturers around the world.
If you write a reminder on a sticky note, eat a bowl of corn flakes for breakfast, blow your nose in a tissue, snack on a chocolate bar, replace batteries in your remote control, wrap leftovers in aluminum foil or put things away in a cardboard box, there’s a good chance Precision Roll Grinders played a big role in it.
Essentially, the company services rollers that range in size from 18 inches to several feet long used in dozens of different industries. It can be for basic maintenance or adjustments for a new line. From flattening paper to refining chocolate to processing the dough for animal crackers to making parts for airplanes and cement manufacturing, Precision has more than 750 monthly clients that send in the rollers they use.
Ed Gumina, president and CEO of Precision Roll Grinders, gives a tour Friday, Oct. 24, 2025, of the Upper Macungie Township-based company, which was recently named the Manufacturers Resource Center business of the year. (April Gamiz/The Morning Call)
Employee Ron Oskika works on a machine Friday, Oct. 24, 2025, at Precision Roll Grinders in Upper Macungie Township, which was recently named the Manufacturers Resource Center business of the year. (April Gamiz/The Morning Call)
Precision Roll Grinders, gives a tour Friday, Oct. 24, 2025, of the Upper Macungie Township-based company, which was recently named the Manufacturers Resource Center business of the year. (April Gamiz/The Morning Call)
Employee Travis Cahoon works on a machine Friday, Oct. 24, 2025, at Precision Roll Grinders in Upper Macungie Township, which was recently named the Manufacturers Resource Center business of the year. (April Gamiz/The Morning Call)
A roll that will be ground to exact precision is seen on Friday, Oct. 24, 2025, of Precision Roll Grinders in Upper Macungie Township. The company was recently named the Manufacturers Resource Center business of the year. (April Gamiz/The Morning Call)
Various rolls that will be ground to exact precision for manufacturing paper, metals and other products, are seen on Friday, Oct. 24, 2025, of Precision Roll Grinders in Upper Macungie Township. The company was recently named the Manufacturers Resource Center business of the year. (April Gamiz/The Morning Call)
Various rolls that will be ground to exact precision for manufacturing paper, metals and other products, are seen on Friday, Oct. 24, 2025, of Precision Roll Grinders in Upper Macungie Township. The company was recently named the Manufacturers Resource Center business of the year. (April Gamiz/The Morning Call)
Various rolls that will be ground to exact precision for manufacturing paper, metals and other products, are seen on Friday, Oct. 24, 2025, of Precision Roll Grinders in Upper Macungie Township. The company was recently named the Manufacturers Resource Center business of the year. (April Gamiz/The Morning Call)
Ed Gumina, president and CEO of Precision Roll Grinders, gives a tour Friday, Oct. 24, 2025, of the Upper Macungie Township-based company, which was recently named the Manufacturers Resource Center business of the year. (April Gamiz/The Morning Call)
Employee Travis Willever works on a machine Friday, Oct. 24, 2025, at Precision Roll Grinders in Upper Macungie Township, which was recently named the Manufacturers Resource Center business of the year. (April Gamiz/The Morning Call)
A roll grinder that will be used in chocolate manufacturing is seen Friday, Oct. 24, 2025, at Precision Roll Grinders in Upper Macungie Township, which was recently named the Manufacturers Resource Center business of the year. (April Gamiz/The Morning Call)
Employee Travis Cahoon works on a machine Friday, Oct. 24, 2025, at Precision Roll Grinders in Upper Macungie Township, which was recently named the Manufacturers Resource Center business of the year. (April Gamiz/The Morning Call)
Various rolls that will be ground to exact precision for manufacturing paper, metals and other products, are seen on Friday, Oct. 24, 2025, of Precision Roll Grinders in Upper Macungie Township. The company was recently named the Manufacturers Resource Center business of the year. (April Gamiz/The Morning Call)
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Ed Gumina, president and CEO of Precision Roll Grinders, gives a tour Friday, Oct. 24, 2025, of the Upper Macungie Township-based company, which was recently named the Manufacturers Resource Center business of the year. (April Gamiz/The Morning Call)
“We grind rollers,” PRG’s President and CEO Ed Gumina said. “If it’s big, and it’s round like a cylinder, and it needs tight tolerances, we grind it in order to make it rounder, and we do the surface finishes as well.”
Founded in 1969, PRG calls itself as the world’s most accurate large roll and cylindrical shaft grinding company, serving customers worldwide. The company can grind rolls up to 50 feet long that weigh up to 140 tons, with tolerances as precise as 20 millionths of an inch (0.00002 inches) — a level of accuracy 200 times thinner than a human hair.
The company recently was honored by the Lehigh Valley’s Manufacturers Resource Center as its 2025 Manufacturer of the Year.
“Precision Roll Grinders represent the pinnacle of manufacturing excellence in the Lehigh Valley,” said Rich Hobbs, president and CEO of the MRC. “Their extraordinary technical grinding precision demonstrates not just mechanical skill, but a commitment to innovation that drives entire industries forward. PRG provides the tightest tolerances in the world — a testament to the advanced manufacturing capabilities that make our region a global leader.”
The privately held company employs about 40 people in the Lehigh Valley and 200 overall, with similar operations in Georgia, Kentucky and Arkansas.
PRG was founded by Adam Schildge — a descendant of the Roebling family, who built the Brooklyn Bridge in 1883 — and Gerhard Syrbius when a customer of Schildge’s Transmares Corp. was interested in purchasing equipment from a German manufacturer. To save time, PRG was formed to provide grinding services in the U.S.
Since the Upper Macungie facility opened in 1970, it has been expanded to accommodate a variety of industries.
“We were initially founded on the plastic and paper industry, but we’ve expanded to so much more, whether it’s wind turbines, gas turbines, land turbines,” said Gumina, who has been with PRG for nine years and was promoted to his leadership role in 2018. “We do rotors, we do plastics, we do rolls for car tires. We do seed oil. We do a lot of food work.”
On the factory floor
A Morning Call reporter and photographer recently toured PRG’s 50,000-square-foot plant on land wedged between Chapmans Road and I-78. On a Friday morning, there was plenty of activity as employees worked on rollers of all sizes. The factory floor is kept at a constant 70 degrees year round because any deviation can affect the rollers.
Foreign companies from Asia, Europe and Australia that send their rollers to be serviced use $500,000 boxes that are filled with nitrogen to prevent the salty air from warping them while they cross the ocean, even by fractions of an inch.
PRG keeps its client list confidential, but companies that were having work done included ones from food and beverage, green energy and paper industries.
“No matter the material, we can grind it,” Gumina said. Rollers can be made of materials including brass, ceramic, steel, granite, copper and rubber.
Gumina said employees are brought in for a lifetime career with the company. He said the company’s turnover rate is 10%; the average in manufacturing is 40%, he said.
“Retention is a priority,” he said.
Victor Schmidt, PRC’s vice president of human resources, said job applicants are tested for their passion for manufacturing. Master grinders need at least five years of training and are necessary for the tightest tolerance on the rollers.
That’s because computers can only get to .005 inches.
“We still use a master grinder to operate the machines because of the method we use to get the tolerance,” Gumina said. “On the computer, it can only get to .005. If you want it tighter than that, you need a master grinder.”
One way PRG keeps its workers from moving to other places is letting them work on research and development projects. Shifting them to R&D lets them stay busy if there is a slow month. It’s also necessary to remain on the cutting edge of technology.
“All workers get excited because they get to play and invent new things and try them out,” Gumina said. “They learn new things. Free to try it out. They stay because they enjoy it.”
These projects usually result in faster machines, better quality products, and clients’ using fewer raw materials and energy, he said.
Gumina said PRC helps keep U.S. companies competitive, by keeping their equipment efficient.
He used the example of a paper mill in a small town: It may be that area’s major employer, and its workers support other businesses.
“We go with every customer to improve their process and compete in the global economy and stay where they are,” Gumina said. “A paper mill in a rural area, when it shuts down it devastates a community. We help customers keep their roots and compete in the global market.”
That type of loyalty is why PRC is staying put in the Lehigh Valley.
“The Lehigh Valley was our very first location and we picked it because it was a good location,” Gumina said. “It was close to the highways. The township was very easy to work with, and the tech schools were amazing. The people here were amazing. So it was a place where we could hire talent, we could train people because this isn’t a trade that you just learn off the street.
“The Lehigh Valley really gave us what we need to succeed.”
Morning Call reporter Evan Jones can be reached at ejones@mcall.com.