Bearings, units and housings -- Super-precision bearings -- Axial-radial cylindrical roller bearings -- Axial-radial cylindrical roller bearings, super-precision -- SKF NRT 325 B
NRT 325 B
Dimensions
| d | 325 | mm | |
| D | 450 | mm | |
| H | 60 | mm | |
| d1 | 415 | mm | |
| C | 20 | mm | |
| H1 | 40 | mm | |
| J | 342 | mm | |
| J1 | 430 | mm | |
| N | 9.3 | mm | |
| N1 | 15 | mm | |
| N2 | 9.3 | mm | |
| a | 8.2 | mm | |
| r1 | min. | 0.6 | mm |
| r2 | min. | 0.6 | mm |
Calculation data
| Basic dynamic load rating - radial direction | C | 134 | kN | |
| Basic static load rating - radial direction | C0 | 450 | kN | |
| Basic dynamic load rating - axial direction | C | 153 | kN | |
| Basic static load rating - axial direction | C0 | 1660 | kN | |
| Attainable speed for grease lubrication | 110 | r/min | ||
| Attainable speed for oil-air lubrication | 220 | r/min | ||
| Axial preload | 12 | kN | ||
| Axial unloading force | 26 | kN | ||
| Frictional moment | CRL | 45 | N·m | |
| Axial stiffness | 28.6 | kN/µm | ||
| Radial stiffness | 8.9 | kN/µm | ||
| Moment stiffness | 427 | kN·m/mrad |
Mass
| Mass bearing | 25 | kg |
Rotary table
| Guideline diameter | 700 | mm |
Mounting information
| Retaining bolts | ||||
| Size | M8 | |||
| Number of bolts | 2 | |||
| Angle between bolts | 180 | ° | ||
| Removal threads | ||||
| Size | G | M12 | ||
| Number of threads | 3 | |||
| Angle between threads | 120 | ° | ||
| Required attachment bolts, shaft | ||||
| Bolt size | M8 | |||
| Pitch | a | 10 | ° | |
| Number of bolts | 34 | |||
| Number of bolts omitted at retaining bolts position | 2, 180° apart | |||
| Tightening torque (Bolt grade 10.9) | 34 | N·m | ||
| Required attachment bolts, housing | ||||
| Bolt size | M8 | |||
| Pitch | a | 10 | ° | |
| Number of bolts | 33 | |||
| Number of bolts omitted at removal thread position | 3, 120° apart | |||