The dimensional and running accuracy of rolling bearings are involved in the tolerance for rolling bearings. There are six of tolerance classes in ISO as 0,6,6X,5,4 & 2,and accuracy grade climbing from the lowest to the highest is corresponding from class 0 to class 2.

	Nominal bore diameter	Nominal outside diameter Single outside diameter Mean outside diameter Deviation of single outside diameter from nominal Deviation of the mean outside diameter from nominal in single plane Outside diameter variation in single radial plane Mean outside diameter variation Nominal width of the outer ring Deviation of single outer ring width Outer rings with variation Radial runout of assembled bearing outer ring Outside inclination variation to outer ring side face Side face runout assembled bearing outer ring with reference to raceway
	Single bore diameter
	Mean bore diameter
	Deviation of single bore diameter from nominal
	Deviation of the mean bore diameter from nominal in single plane
	Nominal diameter at theoretical large end of tapered bore
	Mean diameter at theoretical large end of tapered bore
	Deviation of the mean bore diameter at theoretical large end of tapered bore from nominal
	Bore diameter variation in single radial plane
	Mean bore diameter variation
	Nominal width of the inner ring
	Deviation of single inner ring width
	Inner ring width variation
	Radial runout of assembled bearing inner ring
	Side face runout with reference to bore
	Side face runout of assembled bearing inner ring with reference to racewa
	Nominal width of taper roller bearings
	Deviation of single width of taper roller bearings
	Deviation of mean radial eccentricity in single radial plane