The accuracy of Bearings, dimensional accuracy, shape accuracy and rotation accuracy, is specified by ISO specification or JIS B 1514 specification, etc. Dimensional accuracy refers to the necessary items when installing the bearing on the axle or bearing seat. It means the tolerance or allowable value of inner diameter, outer diameter, width, assembly width, chamfer dimension and conical degree. Shape accuracy means to the allowable values of inner diameter variation, average inner diameter variation, outer diameter variation and average outer diameter variation. The rotation accuracy is the deflection of specified rotation, which means to the allowable values of radial deflection and axial deflection of inner ring and outer ring, lateral deflection of inner ring and outer diameter deflection of outer ring
Technology and equipment are the key factors that restrict the bearing accuracy. The accuracy grade of bearing is JIS 0, 6, 5, 4 and 2, and the accuracy is increased in turn. ABEC scale is a set of scale designed to separate different grades of tolerance used in production and manufacturing of precision bearing (deep groove ball bearing). This scale is developed by the American Bearing Manufacturing Association (ABMA) under the annular bearing Engineering Association / Committee (abbreviated as ABEC). The predecessor of the American Bearing Manufacturing Association (ABMA) is the lubrication bearing manufacturing association.
Abec-1 corresponds to P0
Abec-3 corresponds to P6
Abec-5 corresponds to P5
ABEC-7 corresponds to P4
Abec-9 corresponds to P2
