The single row radial contact ball bearing is the most common rolling bearing. Besides the type series in compliance with boundary dimensions according to ISO
ABEC precision levels, ABEC-1, ABEC-3, ABEC-5, ABEC-7, and ABEC-9 are the equivalent to ISO precision levels P0, P6, P5, P4, and P2 respectively.
Regarding bearing accuracy classes, besides ISO normal accuracy, as . P6. P5. P4. P2. ⎯. ⎯. Ball. ABEC 1. ABEC 3. ABEC 5. ABEC 7. ABEC 9. A60. Bearings.
The radial internal clearance applies to bearings with an inner ring before .. increased accuracy, the tolerances are restricted to values in the classes P6, P5,