Single row cylindrical roller bearings are manufactured in three kinds of basic design: NU, N and NJ. The cylindrical rollers of NU design are axially guided between outer ring guiding ribs, whereas in the N design between inner ring guiding ribs. Both N and NU designs allow mutual displacement of rings axially in both directions and therefore can carry no axial load.



The NJ design has two guiding ribs on outer ring and one rib on inner ring, thus it can accommodate axial force to some extent in one direction. Compared with ball bearings of identical size the cylindrical roller bearings have in average a 60 per cent higher basic load rating and are therefore suitable for high radial loads and are able to operate at high rotational speeds (Unlike ball bearings, cylindrical roller bearings are generally lubricated with oil).