Structures
FC type: These types of bearings have two outer rings with ribs, full set of outer ring (outer ring, rollers, and cages), and an inner ring. Their cages are comb-like structures.
FCD type: These types of bearings have two outer rings with ribs, full set of outer ring (outer ring, rollers, and cages),and two inner rings. Their cages are comb-like structures.

Characters

Four rows cylindrical roller bearings have higher precision for their simple shape of rollers and raceways. They have smaller radial size, higher speed limit, higher dynamic rated load, and higher radial load ability. But they can’t take the axial load. Because of no inner rib, the inner ring and outer ring set, outer ring with rollers and cages, can be installed separately.
For those frequently replaced rolls of cold rolling and hot rolling mill, these bearings have the advantages of high radial load ability, high rotation accuracy, and easy installation. Therefore, they are the first choice for all kinds of rolling mill. 

FC:Double outer races,single inner race,no rib on the inner race.

FCD:Double outer races,double inner races,no rib on the inner race.

FCDP:Double outer races,with only middle rib on and loose rib on the outer race,double inner races,no rib on the inner race.

Applications:

Four-row cylindrical roller bearings are mainly used for heavy machineries, such as mounted on the backup roll of blooming mill, section mill, plate mill, etc.

FEATURES:

Four row cylindrical roller bearings (also called rolling mill bearing) are almost exclusive

Size  available :