Manufactured by CHG Bearing, the NNU4948 is a precision Double Row Cylindrical Roller Bearings. Key dimensional parameters include a 240 mm bore diameter, a 320 mm outer diameter, and a 80 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.

NNU4948 - Double Row Cylindrical Roller Bearings
Technical Specifications
| Overview | |
|---|---|
| Part Number | NNU4948 |
| Brand | CHG® |
| Characteristics | |
| Bearing Type | Double Row Cylindrical Roller Bearing |
| Number of Rows | Double Row |
| Tolerance Class | P0 |
| Dimensions | |
| Bore Diameter (d) | 240 mm |
| Width (B) | 80 mm |
| Outer Diameter (D) | 320 mm |
| Bore Diameter Tolerance | -0.030 – 0 mm |
| Outside Diameter Tolerance | -0.040 – 0 mm |
| Width Tolerance | -0.40 – 0 mm |
| Enveloping Circle Diameter Fw | 263 mm |
| Inner Ring Chamfer | 2.1 min mm |
| Outer Ring Chamfer | 2.1 min mm |
| Performance | |
| Basic Dynamic Load Rating C (kN) | 588 kN |
| Basic Static Load Rating C0 (kN) | 1340 kN |
| Material | |
| Mass (kg) | 18 kg |
| Ring Material | Bearing Steel |
| Rolling Element Material | Bearing Steel |
| Cage Material | Brass |
NNU4948 320 mm 240 mm 263 mm 80 mm Frequently Asked Questions about NNU4948 Double Row Cylindrical Roller Bearings
Find key technical answers regarding dimensions, specifications, and replacement options for this model.
Standard batches of CHG Bearing NNU4948 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 NNU4948 Double Row Cylindrical Roller Bearings under general rotational loads, our application engineers advise an inner-ring shaft tolerance of m5 or k5 for the 240 mm bore. For the 320 mm outer ring, an H7 or J7 housing bore fit is recommended to eliminate creep while accommodating normal thermal gradient expansion.
Built for demanding industrial environments, the NNU4948 Double Row Cylindrical Roller Bearings by CHG Bearing boasts a dynamic load rating (Cr) of standard dynamic and a static load threshold (C0r) of standard static. The optimized internal raceway geometry balances stress distribution, mitigating edge loading even when operating under peak mechanical stresses.
Beyond standard alloy steel, CHG Bearing can customize the NNU4948 Double Row 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.
