To the naked eye, a ball screw looks like something you might pick up at the corner hardware store.

The ball screws produced by Aero Precision Products in Summerville most definitely aren’t something bought over the counter.

Aero is one of about four companies in the world that produces ball screws for the aerospace industry. Although ball screws are used in other applications, the requirements are different.

For machine tools, for example, users are most concerned about position accuracy.

In the aerospace industry “if you make it for an airplane and you don’t make it right, really bad things happen,” said company president John Kinney.

If you were to peer into the inner workings of a ball screw, you would see ball bearings lined up in grooves that allow the balls to recirculate, traveling around and around the screw without ever falling out. The design translates rotational movement to linear movement, can withstand large loads and loses little energy to friction – those that Aero produces must test at no less than 10 percent energy loss.

Ball screws are used in the flight control systems for airplanes, drones, rockets and missiles. They can be tiny – the ball bearings so small they resemble the sugar pearls sprinkled on cakes – or large, sturdy enough to lift 60,000 pounds.

Aero Precision was started six years ago and moved to its current location on Deming Way two years ago. It employs 12 people in Summerville and has four engineers in Michigan.

Kinney, a mechanical engineer, moved to the Lowcountry from Michigan 13 years ago. He ran the Walterboro plant for RBC Bearings until it moved to Texas, and that’s when he started Aero Precision as a subsidiary of Mistequay Group Ltd.

“We’re having fun,” Kinney said. “We’re trying to grow.”