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.
aim9e/j/p end item identification, 0.2498 inches nominal bore diameter, aligning ring features provided, radial load direction, 0.0007 inches minimum radial and 0.0010 inches maximum radial internal clearance