Double-row cylindrical Roller BearingsModelNameFeaturesNNDouble-row cylindrical roller bearings without outer ring ribsBearings of this type have high radial rigidity and are used primarily for spindle of precision machine tools. No axial loads can be sustained, can not limit the axial displacement of shaft and housing.Often used as free-end bearings.NNUDouble-row cylindrical roller bearings without inner ring ribsSame as above