In the metallurgical industry, rolling mill bearings are used under very harsh conditions featuring heavy load, high impact load, high temperature, water vapor and dusty environment. Rolling mill production line uses four row cylindrical roller bearings to support radial load, and thrust roller bearings or thrust ball bearings, radial angular contact ball bearings or radial roller bearings to support axial load. Four row cylindrical roller bearings are mainly used as main roller bearings in metallurgical equipment. Due to their compact structure, good rigidity and high bearing capacity, they are widely used as rolling mill bearings. Because their inner ring has no flange, they cannot bear axial load.