cylindical roller bearing size:N,NJ,NU,NUP series cage:cooper and iron cages material:bearing ... must be press-fitted. It can be grouped into NU,NJ, NUP,N, NF etc. one-row bearing, and NNU, ... to a certain extent, relative to the housing position6 The NJ and NF types carry a certain degree of axial displacement ... these bearings according to customer's drawings and samples NJ,NU series roller bearing