Bearing Precision Levels 

Machine tool builders can choose from different levels or classes of bearing precision to meet their specific requirements.  Timken tapered roller bearings are available in a complete range of precision classes.  This table provides broad guidelines for bearing class selection.


From lowest to highest precision


Class C / 3

  • Low precision machines
  • Drills
  • Conventional lathes
  • Milling machines
  • Precision gear drives


Class B / 0

  • NC lathes
  • Milling/boring machines
  • Machining centers


Class A / 00

  • Grinding machines
  • Jig boring machines
  • Workpiece spindles (cylindrical grinder)


Class AA / 000

  • High accuracy machines
  • Precision measuring instruments
  • Special applications