The four-row cylindrical roller bearing is a typical rolling mill roll diameter bearing. The ring and rolling element components can be easily separated from each other, high precision can achieve parts interchange, installation, disassembly and cleaning are very convenient, and it is installed in a given radial direction. In the space, it can provide a larger radial bearing capacity and a lower friction coefficient. Four-row cylindrical roller bearings have three main structural types, namely: FC type, FCD type and FCDP type.

In order to accommodate a large number of rolling elements to provide excellent radial load-bearing capacity, the cage of four-row cylindrical bearings with an inner diameter of 400mm or more is generally designed as a pin-type cage. This cage consists of laterally limited rolling elements. It consists of two washers connecting the two washers and passing through the center of the roller. It consists of 2 inner rings, 2 outer rings, 4 rows of rolling elements, 1 middle retaining ring, 2 side retaining rings, and 4 retaining rings. The two ends of the pillar and the gasket are fixed by argon arc welding and riveting. The retainer has high strength. This is very important for SKF bearings that are subject to frequent shocks or subject to large acceleration and deceleration movements (such as: section steel billeting mills, high-speed reversible rolling mills).