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.
White Paper on bearing tolerance and precision levels including definitions and specifications of ABEC and RBEC precision levels . ABEC 9, Class 2, P2
Bearlng accuracy are respectlvely P0, P6 , P5 , P4 and P2 flve class , whose accuracy Increased. Multiple level rolling mill block bearing P4 Tolerance class.