The two-row ball slewing bearing has three seat-rings. The steel balls and the retainers may be directly arranged into the upper and lower racers. Two rows of steel balls with different diameters are fitted according to the force. Such open type fitting is extraordinary convenient, the loading angels at upper and lower races are 90 which can carry both of the axial force and capsizing moment. When the radial force is larger than 1/10 of the axial force, the races should be newly designed.

1 Bearing surface is covered with the anti-rust oil first; and then wrapped with the plastic film;

       2 And then packed with craft paper and professional belts;

       3 At last, with wooden box totally at the outer packing to invoid the rust or the moist;

       4 We can depend on the customers demand to be packed;

   Larger dimension of axial and radial, compact structure.

 Tower cranes which require working radius over medium range, auto crane and loading (unloading) machinery.