Backing bearing mainly used for cold cluster rolling mill's roller. This mill take the bearing's outer ring as working surface, generally there's 3 or 5set bearings mounted on each roller and even more, depending on its matching rule. The bearing has thick outer ring and thin inner ring, high accuracy up to abec-7. Cylindrical roller bearing based on two or three rows of rollers and are available as full complement bearings (without cage) or as caged bearings. The advantage of the bearings without flanges lies in their particularly simple geometrical form and their very high radial load carrying capacity. Cylindrical roller backing bearings without flanges or flange rings cannot accommodate any axial load. So it is necessary to position thrust washers of bronze or plastic between the side faces of the outer ring and the support saddles. Thrust washers are not required with backing bearings with flanges (or flange rings) as the design of these bearings enables them to accommodate simultaneously acting radial and axial forces. For different requirement, zsj's backing bearing could fall in 2 classes by material: vacuum-degassed bearing steel and electroslag cemented bearing steel. Combined with advanced heat-treatment, grinding process, the bearing's quality is highly reliable. Zsj standard packing