32207-A 35mm Taper Roller Bearing, 72mm O.D. apered roller bearings comprise solid inner and outer rings with tapered raceways and tapered rollers in a window cage. Open bearings are not self-retaining. As a result, the inner ring with the rollers and the cage can be fitted separately from the outer ring. Metric and inch size bearings are available. Designs with a K in the designation have inch dimensions. For new designs, however, bearings in metric sizes should always be used in preference.