A range of inch rings (0.08 in to 6 in) in three grades of accuracy (AA, A and B). Accuracy of geometric form, maximum departures of mean measured size from nominal size, accuracy to which the measured size is to be determined. Also includes material, hardness, and surface texture.
BS 4065:1966 history
0000 BS 4065:1966(1999)
1966BS 4065:1966 Specification for plain setting rings for use with internal diameter measuring machines - Inch units