They are the most widely used bearings for various rolling mills in the metallurgical industry.There are so many  main characteristics,a.The bearings take on the largest value of dynamic load rating in limited space;b. They can be used for high speed;c. The bearings allow precise limiting tolerance;d. The inner ring and outer components (outer ring, complete sets of rollers) are interchangeable, advantageous to quick roll changing;e. The bearings can bear radial load only.