Manufactured by CHG Bearing, the NNU 4960 BK/SPW33 is a precision Super-Precision Cylindrical Roller Bearings. Key dimensional parameters include a 300 mm bore diameter, a 420 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 4960 BK/SPW33 - Super-Precision Cylindrical Roller Bearings
Technical Specifications
| Overview | |
|---|---|
| Part Number | NNU 4960 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) | 300 mm |
| Width (B) | 118 mm |
| Outer Diameter (D) | 420 mm |
| Minimum Chamfer Dimension rmin | 2.5 mm |
| Inner Ring Chamfer | 3 mm |
| Outer Ring Chamfer | 1.1 mm |
| End-face Height Difference h | 5.5 mm |
| Outer-Ring Land Diameter (L2 / D1) | 379 mm |
| Inner Ring Raceway Diameter F | 339 mm |
| Shaft Shoulder Diameter dₐ, min. | 313 mm |
| Shaft Shoulder Diameter dₐ, max. – NNU Design | 335 mm |
| Housing Shoulder Diameter Dₐ, max. | 407 mm |
| Performance | |
| Basic Dynamic Load Rating C (kN) | 1020 kN |
| Basic Static Load Rating C₀ (kN) | 2360 kN |
| Limiting Speed – Grease (r/min) | 1800 r/min |
| Limiting Speed – Oil-air (r/min) | 2000 r/min |
| Reference Grease Quantity Gref (cm³) | 420 cm³ |
| Fatigue Load Limit Pᵤ (kN) | 224 kN |
| Material | |
| Lubrication Groove Width | 16.7 mm |
| Lubrication Holes (qty × Ø mm) | 3 |
| Weight (kg) | 49.6 kg |
| Radial Internal Clearance | C1 mm |
| Internal Design & Weight | |
| Cage Type | Machined Metal Cage |
| Mounting Dimensions | |
| Lubrication Port Thread / Size Φ1 | 342 |
NNU 4960 BK/SPW33 420 mm 300 mm 118 mm Frequently Asked Questions about NNU 4960 BK/SPW33 Super-Precision Cylindrical Roller Bearings
Find key technical answers regarding dimensions, specifications, and replacement options for this model.
In its sealed configuration (Open Type), CHG Bearing pre-charges NNU 4960 BK/SPW33 with premium wide-temperature lithium-complex or polyurea grease, calibrated to a 30%–35% cavity volume ratio. For open-type variants, synthetic PAO or refined mineral lubricating oils with appropriate EP (Extreme Pressure) additives should be circulated.
For international ocean and air freight, CHG Bearing packs NNU 4960 BK/SPW33 with industrial VCI anti-corrosion barrier wrapping, sealed polybags, individual cartons, and fumigated ocean-worthy wooden crates. This multi-layer barrier guarantees rust-free storage for a minimum shelf life of 24 to 36 months.
When fitting NNU 4960 BK/SPW33 over a 300 mm shaft, CHG Bearing strictly recommends uniform induction heating (controlled between 90°C and 110°C) or precision hydraulic press sleeves. Under no circumstances should direct impact blows be struck against the rings or cage, as shock loads cause brinelling indents and premature spalling.
Beyond standard alloy steel, CHG Bearing can customize the NNU 4960 BK/SPW33 Super-Precision Cylindrical Roller Bearings using AISI 440C stainless steel, black oxide coating, zinc-nickel plating, or hybrid ceramic (Si3N4) balls for applications involving chemical exposure, marine salt fog, or galvanic current hazards.
