In the metallurgical industry, rolling mill bearings work in heavy load, high impact load, high temperature, water vapor and dusty environment, and the working conditions are very bad. The rolling mill production line uses four-row cylindrical roller bearings to support radial load, thrust roller or thrust ball bearings, and radial angular contact ball or radial roller bearings to support axial load. Four-row cylindrical roller bearings are mainly used as main roller bearings in metallurgical equipment. Because of its compact structure, good rigidity and high bearing capacity, it is a widely used rolling mill bearing. Because the inner ring has no rib, it cannot bear axial load.