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.
machined retainer fabrication method, unable to decode material, pair of bearings,back to back mtg; inner ring runout 0.0005 in. max; outer ring runout 0.0005 in. max special features, 0.0002 inches minimum radial and 0.0005 inches maximum radial and 0.0003 inches minimum axial and 0.0006 inches maximum axial internal clearance, radial load direction