DS EN 3291:1994 Aerospace Series - Bearings, Airframe Rolling - Single Row Self-Aligning Roller Bearings In Steel, Cadmium Plated - Diameter Series 3 And 4 - Dimensions And Loads Defines characteristics of single row self-aligning roller bearings in steel, cadmium plated, of diameter series 3 and 4 designed to withstand only slow rotations, oscillations and/or swivelling under