Single-Row Cylindrical Roller Bearing NNU49/530A In bearings of this type, the cylindrical rollers are in linear contact with the raceways. They have a high radial load capacity and are suitable for high speeds. There are different types designated as NU, NJ, NUP, N, NF (for single-row bearings), NNU, and NN (for double-row bearings depending on the design or absence of side ribs). The outer and inner rings of all types are separable.