Manufactured by CHG Bearing, the NNU 4968 BK/SPW33 is a precision Super-Precision Cylindrical Roller Bearings. Key dimensional parameters include a 340 mm bore diameter, a 460 mm outer diameter, and a 118 mm overall width. This component is designed to meet standard load requirements and ensure consistent operational performance. For comprehensive technical evaluation, please explore the detailed specifications, dimensional data, product images, and CAD drawings provided below. A complete PDF data sheet is also readily available for direct download to support your engineering and procurement needs.
NNU 4968 BK/SPW33 - Super-Precision Cylindrical Roller Bearings
Technical Specifications
| Overview | |
|---|---|
| Part Number | NNU 4968 BK/SPW33 |
| Brand | CHG® |
| Characteristics | |
| Bearing Type | Super-precision Cylindrical Roller Bearing |
| Design Type | Tapered Bore 1:12 |
| Structure (Drawing Reference) | Complete Bearing |
| Number of Rows | 2 |
| Ring Type | None |
| Design | NNU Design |
| Tolerance Class | SP |
| Bearing Material | Bearing Steel |
| Coating | None |
| Sealing | None |
| Lubricant | None |
| Features | Annular Lubrication Groove and Lubrication Holes |
| Number of Flanges – Outer Ring | 3 |
| Number of Ribs – Inner Ring | 0 |
| Dimensions | |
| Bore Diameter (d) | 340 mm |
| Width (B) | 118 mm |
| Outer Diameter (D) | 460 mm |
| Minimum Chamfer Dimension rmin | 2.5 mm |
| Inner Ring Chamfer | 3 mm |
| Outer Ring Chamfer | 1.5 mm |
| End-face Height Difference h | 5.5 mm |
| Outer-Ring Land Diameter (L2 / D1) | 419 mm |
| Inner Ring Raceway Diameter F | 379 mm |
| Shaft Shoulder Diameter dₐ, min. | 353 mm |
| Shaft Shoulder Diameter dₐ, max. – NNU Design | 375 mm |
| Housing Shoulder Diameter Dₐ, max. | 447 mm |
| Performance | |
| Basic Dynamic Load Rating C (kN) | 1100 kN |
| Basic Static Load Rating C₀ (kN) | 2650 kN |
| Limiting Speed – Grease (r/min) | 1500 r/min |
| Limiting Speed – Oil-air (r/min) | 1700 r/min |
| Fatigue Load Limit Pᵤ (kN) | 245 kN |
| Material | |
| Lubrication Groove Width | 16.7 mm |
| Lubrication Holes (qty × Ø mm) | 9 |
| Weight (kg) | 56.1 kg |
| Radial Internal Clearance | C1 mm |
NNU 4968 BK/SPW33 460 mm 340 mm 118 mm Frequently Asked Questions about NNU 4968 BK/SPW33 Super-Precision Cylindrical Roller Bearings
Find key technical answers regarding dimensions, specifications, and replacement options for this model.
Each NNU 4968 BK/SPW33 produced in CHG Bearing manufacturing facilities features accurately profiled corner chamfers complying with DIN 5412 / ISO standard corner radii. When designing mating shafts and housing shoulders, machining an undercut or fillet radius strictly within the inner ring clearance limit (340 mm bore side) ensures perfect planar contact without edge binding.
To extend the trouble-free lifespan of CHG Bearing NNU 4968 BK/SPW33, preventive maintenance routines should monitor operating housing temperature (normally maintaining below 70°C) and conduct regular vibration FFT analysis to identify early raceway micro-pitting before unexpected line halts occur.
Standard batches of CHG Bearing NNU 4968 BK/SPW33 conform strictly to ISO Class Normal (ABEC-1). For high-precision machine tool spindles, gearboxes, or robotics requiring tighter runouts, CHG Bearing can provide custom batches graded to ISO Class 6 (P6/ABEC-3) or ISO Class 5 (P5/ABEC-5) with 100% micrometer verification.
To ensure optimum performance of CHG Bearing NNU 4968 BK/SPW33 Super-Precision Cylindrical Roller Bearings under general rotational loads, our application engineers advise an inner-ring shaft tolerance of m5 or k5 for the 340 mm bore. For the 460 mm outer ring, an H7 or J7 housing bore fit is recommended to eliminate creep while accommodating normal thermal gradient expansion.
