Two single row annular ball bearings selected dimensionally to be a matched pair or set. The ring faces have been specially ground to specified offsets that will produce predetermined preload when mounted. May include a single row angular contact bearing with faces specially ground for duplex mounting.
mil-g-25537 mil spec single material response lubrication material document and classification, 3.9370 inches nominal overall outside diameter, 1.3774 inches nominal bore diameter, 0.0048 inches minimum radial and 0.0058 inches maximum radial internal clearance, radial load direction