When the bearings bear bigger radial load, four row taper roller bearings also can bear axial load at two directions at the same time, but their allowable rotation speed is not high. They are mainly used in rolling bearing of rolling mill. The bearings with medium and small size are made of bearing steel; large-sized four row taper roller bearings are made of carburizing steel. Hollow roller and pillar retainer are adopted for bearings with especially big size, in order to prolong service life of bearings.