BC4B 319991/HA4 bearings ( 773.334 mm x 1120 mm x 800 mm) have the advantages of Extremely high radial load capacity, high rigidity, separable design, and are therefore widely used in the metallurgical rolling mills, large gearboxes, and heavy-duty extrusion presses.

| Part Number | BC4B 319991/HA4 |
| Interchangeable | SKF BC4B 319991/HA4 |
| Bearing Type | Four-row cylindrical roller bearing for rolling mills |
| Cage | Machined brass cage |
| Seal | Open |
| Bore Type | Cylindrical bore |
| Series | BC4B 3199../HA4 |
| Coating | No |
| Units | Metric |
| Weight [lb] | 5985.489 |
| Bearing part | Complete |
| Heat stabilized | 150 °C(300 °F) |
| Cr Radial Dynamic [lbf] | 5350063 |
| C0r Radial Static [lbf] | 14724188 |
| Dimension | |
| d φ Inside [inch] | 30.446 |
| D Φ Outside [inch] | 44.094 |
| B Inner Width [inch] | 31.496 |
| C Outer Width [inch] | 31.496 |
The BC4B 319991/HA4 Four-row cylindrical roller bearings mainly consist of an inner ring, an outer ring, four rows of cylindrical rollers, a cage, and a spacer. Common structures use a configuration of double outer rings (each with double raceways) and a single inner ring (with four raceways), or an interchangeable combination of inner and outer rings. Axial positioning and load distribution are achieved through the spacer.
The advantages of four-row cylindrical roller bearings are their extremely high radial load capacity, high rigidity, and the line contact between the rollers and raceways, resulting in a low coefficient of friction and allowing for high-speed operation under heavy loads. They can also be used as floating end bearings, capable of withstanding axial displacement caused by thermal expansion, and are easy to install and maintain.















