ZWKZ can produce this kind of bearings with N, NU, NJ, NF, NUP, NH (NJ HJ), NN, NNU, FC, FCD structure. In view of four row cylindrical roller bearings' using conditions for rolling mill, we put more energy and time to reserarch and develop, solve many technical problems, now have many products already applied for national patent. The inner diameter are ?100~?950mm.