Manufactured by CHG Bearing, the NNU4956K/W33 is a precision Double Row Cylindrical Roller Bearings. Key dimensional parameters include a 280 mm bore diameter, a 380 mm outer diameter, and a 100 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.

NNU4956K/W33 - Double Row Cylindrical Roller Bearings
Technical Specifications
| Overview | |
|---|---|
| Part Number | NNU4956K/W33 |
| Brand | CHG® |
| Characteristics | |
| Bearing Type | Double Row Cylindrical Roller Bearing |
| Number of Rows | Double Row |
| Tolerance Class | P0 |
| Dimensions | |
| Bore Diameter (d) | 280 mm |
| Width (B) | 100 mm |
| Outer Diameter (D) | 380 mm |
| Bore Diameter Tolerance | -0.035 – 0 mm |
| Outside Diameter Tolerance | -0.040 – 0 mm |
| Width Tolerance | -0.30 – 0 mm |
| Enveloping Circle Diameter Fw | 312 mm |
| Inner Ring Chamfer | 2.1 min mm |
| Outer Ring Chamfer | 2.1 min mm |
| Performance | |
| Basic Dynamic Load Rating C (kN) | 791 kN |
| Basic Static Load Rating C0 (kN) | 1860 kN |
| Material | |
| Mass (kg) | 33 kg |
| Ring Material | Bearing Steel |
| Rolling Element Material | Bearing Steel |
| Cage Material | Brass |
| Lubrication Groove Width | 12.2 mm |
| Lubrication Holes (qty × Ø mm) | 3 × Ø6 |
NNU4956K/W33 380 mm 280 mm 312 mm 100 mm Frequently Asked Questions about NNU4956K/W33 Double Row Cylindrical Roller Bearings
Find key technical answers regarding dimensions, specifications, and replacement options for this model.
Yes, CHG Bearing works closely with industrial OEMs and brand distributors. We offer turnkey custom engineering for NNU4956K/W33, including laser-etched customer logos, custom internal radial clearances, specialized grease formulations, and bespoke protective packaging.
To safeguard CHG Bearing NNU4956K/W33 against fretting wear and false brinelling during transport or vibration, assemble mating surfaces (280 mm x 380 mm) using anti-fretting mounting paste. Maintaining strict alignment and avoiding prolonged static vibration will preserve raceway polish.
Standard batches of CHG Bearing NNU4956K/W33 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.
When fitting NNU4956K/W33 over a 280 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.
