Classification of bearings
An arbitrary system for the grouping of bearings according to their accuracy. The bearings are grouped into one or other of the four following classes
Class A bearings in which there is a probability of less than 1 in 20 that the bearing error would exceed +/-2 degrees
Class B bearings in which there is a probability of less than 1 in 20 that the bearing error would exceed +/-5 degrees
Class C bearings in which there is a probability of less than 1 in 20 that the bearing error would exceed +/-10 degrees
Class D bearings in which the error would exceed +/-10 degrees
Reference: I.T.U.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
