Tapered thrust bearings are specially designed for heavy axial loads. The profile of tapered bearings ensures optimal distribution of stress across the roller/race. The special design of the surfaces of the flange and the large roller help to move the lubricant into the roller and the flange contacts. Tapered thrust bearings are used in slow moving situations subject to heavy loads; a tapered thrust bearing can often be used where the axial load of any other bearing is lacking, for example in the large fans in nuclear power stations.