MIL-B-913/13
BEARING, BALL, ANNULAR, FOR INSTRUMENTS AND PRECISION ROTATING COMPONENTS, ANGULAR CONTACT, UNFLANGED, SEPARABLE AND STEPPED INNER RING, CHROMIUM-ALLOY STEEL, ABEC 5P (METRIC)
BEARING, BALL, ANNULAR, FOR INSTRUMENTS AND PRECISION ROTATING COMPONENTS, ANGULAR CONTACT, UNFLANGED, SEPARABLE AND STEPPED INNER RING, CHROMIUM-ALLOY STEEL, ABEC 5P (METRIC)