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-23827 mil spec single material response lubrication material document and classification, contact bearing seal type, 0.0010 inches minimum radial and 0.0014 inches maximum radial internal clearance, 40.0 pounds minimum bearing preload rating, 35.0 millimeters nominal bore diameter