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.
navy sea systems command (timken/skf-bearing ball duplex) part name assigned by controlling agency, assembly,propeller end item identification, unable to decode material, cage silver precious material and location, silver precious material