The rolling speed is fast, the pollution is serious, the impact force is large, and the overall strength of the bearing is relatively high. Four high rolling mill: back-up roller bearings generally use four-row cylindrical roller bearings and double-row thrust tapered roller bearings. Work roll bearings: four-row cylindrical roller bearings and double-row angular contact (deep groove ball) bearings. Two high rolling mill: Roll bearings are generally configured: four-row cylindrical roller bearings and double-row thrust tapered roller bearings or double-row angular contact bearings.