NNU 6040 M bearings ( 200 mm x 310 mm x 200 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 | NNU 6040 M |
| Interchangeable | SKF NNU 6040 M |
| Outer ring | RNNU 6040 M |
| Inner ring | LNNU 6040 |
| Bearing Type | Six-row cylindrical roller bearing |
| Cage | Machined brass cage |
| Seal | Open |
| Bore Type | Cylindrical bore |
| Series | NNU 60.. M |
| Coating | No |
| Units | Metric |
| Weight [lb] | 132.276 |
| Bearing part | Complete |
| Heat stabilized | 150 °C(300 °F) |
| Cr Radial Dynamic [lbf] | 301042 |
| C0r Radial Static [lbf] | 730091 |
| Pu Fatigue load limit [lbf] | 76064 |
| Dimension | |
| d φ Inside [inch] | 7.874 |
| D Φ Outside [inch] | 12.205 |
| B Inner Width [inch] | 7.874 |
| C Outer Width [inch] | 7.874 |
| D1 [inch] | 9.764 |
| F [inch] | 9.134 |
| r1, r2(min.) [mm] | 2.1 |
| r3, r4(min.) [mm] | 2.1 |
| K lubrication hole [inch] | 0.118 |
| s Permissible axial displacement [inch] | 0.236 |
| kr Calculation coefficient | 0.5 |
The NNU 6040 M 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.















