All Special purpose ball bearing-TM ball bearing Inner diameter 17-70 mm Special purpose ball bearing-gyroscope use Inner diameter 1.016-9.525 mm Metric series Inner diameter 1-4 mm Metric series Inner diameter 5-9 mm Metric series, with stop edge, inner diameter 1-4 mm Metric series, with stop edge, inner diameter 5-9 mm English series Inner diameter 1.016-9.525 mm English series, with stop edge, inner diameter 1.191-9.525 mm