Cylindrical roller thrust bearings are designed to accommodate heavy axial loads and impact loads. They must not be subjected to any radial load. The bearings are very stiff and require little axial space. Bearings in the 811 and 812 series with one row of rollers are mainly used in applications where thrust ball bearings do not have sufficient load carrying capacity. Depending on their series and size, cylindrical roller thrust bearings are fitted with A Glass fibre reinforced PA66 cage (suffix TN) or a machined brass cage (suffix M).