The manufacturing process used to manufacture a ball bearing’s and outer rings is almost identical.

  1. The rings start out as tube stock. Automatic machines similar to lathes, such as screw machines, use cutting tools to cut the rings to the basic shape, leave extra material for machining.
  2. Outer ring faces are stamped with bearing number and manufacturer imformation.
  3. The next step in the process of ring manufacturing is hardening. the rings are heated to a temperature of 1565 degrees F for 15-20 minutes, quenched in oil at 375 degrees F for 15-20 minutes and then tempered at 340 degrees F for 2 hours.
  4. The next steps in the process of both inner and outer rings are grinding by specialized grinding machines to achieve the finished dimensions.
    • Face grinding to acheive proper bearings width
    • OD grinding for outer rings and bore grinding for inner rings
    • Race grinding for proper radius, race location and geometry
  5. The final manufacturing step is honing of the races for proper surface finish and geometry.

Additional steps may be required for some bearings. for examples angular contact bearings may need additional face grinding to ensure that the inner and outer rings are the same width when the bearing in under a thrust load.

Even if the inner and outer rings start out the exact same width, many factors may cause them to be misaligned when the bearings is assembled and under load, such as variance in race radius, race location, race, race geometry and ball diameter.