Cylindrical roller bearings and units are used for all kinds of railway rolling stock. These bearings are typically applied as sets of two single row bearings. The rollers in a single row cylindrical roller bearing are guided between the integral “open” flanges of the outer rings. These “open” flanges, combined with the specially designed and surface treated roller ends, provide improved lubrication reduced friction and consequently lower operating temperatures. The outer ring with the integral flanges, together with the cylindrical roller and cage assembly, can be separated from the inner ring. This enables easy mounting and dismounting.