Bearing balls are special highly spherical and smooth balls, most commonly used in ball bearings, but also used as components in things like freewheel mechanisms. The balls come in many different grades. These grades are defined by bodies such as the American Bearing Manufacturers Association (ABMA), a body which sets standards for the precision of bearing balls. They are manufactured in machines designed specially for the job. In 2008, the United States produced 5.778 billion bearing balls.