No one could ever have imagined in 1913 when Leander Hoover founded the Hoover Steel Ball Co. in Ann Arbor just how much growth and change the future would hold. The future would entail a series of acquisitions, an eventual move from the bottom of the Lower Peninsula to the top of the Upper Peninsula in Sault Ste. Marie, becoming part of a worldwide Japanese manufacturing giant, and 107 years later, a product expansion from its beginning making a few kinds of ball bearings to offering thousands of SKUs. Those products have a range of size and function that Leander Hoover would have thought impossible. The Sault operation of what is now called TN Michigan LLC makes balls as small as 62-thousandths of an inch in diameter and as large as six inches. Some balls require such a level of precision that they have to be within three-millionths of absolute roundness.

The balls they make go into such mundane things as printers and Windex bottles but also into fracking rigs, respirators and COVID-19 tests. Hoover began its expansion in 1924 with the acquisition of a Detroit company called Imperial Bearings Co.; in 1955 it merged with a die-casting company; and in 1958 it bought two more manufacturing companies. The move to the Sault was a process that began in 1968, when a company called Ultraspherics Inc. was launched with a focus on making plastic balls. In 1978, Ultraspherics moved to Sault Ste. Marie and in 1983 was acquired by Hoover, which changed its name to Hoover Precision Products LLC.

In 1990, Tsubaki Nakashima Co. LTD of Japan bought Hoover and later changed Hoover's name to TN Michigan LLC. The Sault plant employs about 70 and makes balls made of metal, plastic, tungsten carbide, nylon, Teflon, Torlon, polypropylene, polyethylene, polystyrene, cobalt oxide and aluminum oxide, with applications for auto, marine, aerospace and, in particular, medicine.

"Buying Hoover got Tsubaki into the United States, and it got us into the rest of the world," said Terry Adams, the manager of the Sault plant, an engineering graduate of nearby Lake Superior State University who has been working at the company since 1983. "When I graduated from college, I drew a 100-mile circle around Sault Ste. Marie, and that was as far as I was going to go for a job," said Adams. "My wife is from the Sault, too, and we weren't going to go far."

He said today the plant ships about 50 percent of production outside the U.S.

The plant was deemed an essential business when the coronavirus hit. Its products are used in thousands of different medical devices and products, and they are an important component of respirators and COVID-19 test kits. Many of the medical components are made in the company's 8,000-square-foot Class 100 clean room to ensure sterile manufacturing conditions. The plant has 68,000 square feet in all.

"We expanded that business sharply," said Adams of parts sold to companies making products and devices used to test or treat COVID patients. "We were getting a lot of calls. The work helped us fill a few open positions. We didn't have to add any equipment, but there was a lot of overtime."

Tsubaki Nakashima has 20 plants on three continents. The American subsidiary, TN Americas Holdings Inc., is headquartered in Cumming, Ga. It has four manufacturing plants in the U.S, one in Georgia, two in Tennessee and the one in Michigan.

The other three plants in the U.S. have a heavy auto focus, so production there was cut back substantially as COVID shut down auto plants.

"We carried the company the last few months," said Adams. "I joke with the other plant managers, 'It's getting tough carrying you guys.'"

But even before COVID, Adams said the parent company was planning on growing Sault operations. "Our margins are better than the auto suppliers," he said.

Non-medical products made in the Sault include balls that control the volume and velocity of triggered sprayers such as those used in hand sanitizers and ink-jet printers. "Almost everyone with a printer has our balls," said Adams.

He said one medical-supply customer buys 27 million quarter-inch polystyrene balls a month.

Adams said revenue has been growing annually and should hit $20 million this year, up from about $16 million in 2018.

The plant floor runs 24/7, with some employees on eight-hour shifts and others working a schedule of on for three 12-hour shifts, off two days, then back on. Adams said payroll and local purchases exceed $4 million a year, an important impact in a city whose population was estimated at about 13,500 in 2018.

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