A NU303 is a single-row cylindrical roller bearing (CRB) with a NU design. This bearing features two rigid ribs on its outer ring and none on its inner ring. As a result, NU bearings can only accommodate radial forces. This kind of bearing is frequently utilized as a floating bearing, enabling the shaft to move axially in either direction with respect to the housing. This is necessary in situations when temperature fluctuations cause the shaft material to shrink or expand.