Rolling bearing precision is mainly divided into: the size precision and the rotating precision.
Bearing precision grade standards, divided into level 0 , level 6X, level 6, level 5, level 4, level 2 ,six grades.
Bearing precison enhanced from 0 levels, to the general bearing,level 0 is enough, but when used in other conditions or situations,
it requires level 5 or higher
Athough above precision grade is formulated based on ISO standard, but its name be different in different national.