Tech Brief – Bearing seal cross-section We manufacture and use Angular Contact Bearings(ACB) for our headsets. We use only the best manufacturing and quality control methods available. The manufacturing process begins with the rough shape of the bearing races being machined from high quality steel. Both the inside and outside of each race is then precision stone- ground to reach its final shape. Computer controlled grinding equipment is used to grind each race to exact tolerances. The races are then assembled with the balls to create the finished bearing.