Manufactured by CHG Bearing, the 28.91*30.2 is a precision Tapered Rollers. Key dimensional parameters include a mm bore diameter, a mm outer diameter, and a 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.
28.91*30.2 - Tapered Rollers
Technical Specifications
| Overview | |
|---|---|
| Part Number | 28.91*30.2 |
| Brand | CHG® |
| Product Type | Tapered Roller |
| Taper Angle | 2° |
| Dimensions | |
| Roller Length, Lw | 30.2 mm |
| Center Recess Diameter | 12 mm |
| Through-hole Diameter | - mm |
| Center Recess Depth | 1 mm |
| Large-end Diameter, Dw | 28.91 mm |
| Spherical End Radius, SR | 393 mm |
| Through-hole Chamfer | - mm |
| Large-end Diameter Tolerance | -0.01 to +0.016 mm |
| Through-hole Coaxiality | - mm |
| Rolling Surface Roughness, Ra (µm) | 0.125 |
| Axial Chamfer — Large End | 1.2 mm |
| Axial Chamfer Tolerance — Large End | -0.2 to +0.2 mm |
| Radial Chamfer — Large End | 1 mm |
| Radial Chamfer Tolerance — Large End | -0.2 to +0.2 mm |
| Axial Chamfer — Small End | 1 mm |
| Axial Chamfer Tolerance — Small End | -0.2 to +0.2 mm |
| Radial Chamfer — Small End | 1.2 mm |
| Radial Chamfer Tolerance — Small End | -0.2 to +0.2 mm |
| Performance | |
| Spherical End Surface Roughness, Ra (µm) | 0.16 µm |
| Dimensional & Geometrical Accuracy | |
| Roller Length Tolerance | -0.4 to 0 mm |
| End-face Runout | - mm |
| Diameter Variation Between Ends | ±0.003 mm |
| Roundness | 0.0015 mm |
| Ovality | 0.0015 mm |
28.91*30.2 28.91 mm 30.2 mm 393 mm Frequently Asked Questions about 28.91*30.2 Tapered Rollers
Find key technical answers regarding dimensions, specifications, and replacement options for this model.
Following standard ISO 281 fatigue calculation guidelines, the nominal rating life (L10) of CHG Bearing 28.91*30.2 correlates its dynamic capacity (standard dynamic) with equivalent dynamic loads. In controlled industrial settings with proper contamination-free filtration, field data confirms continuous operational longevity exceeding 20,000 to 50,000 service hours.
In its sealed configuration (Open Type), CHG Bearing pre-charges 28.91*30.2 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.
To ensure optimum performance of CHG Bearing 28.91*30.2 Tapered Rollers under general rotational loads, our application engineers advise an inner-ring shaft tolerance of m5 or k5 for the mm bore. For the mm outer ring, an H7 or J7 housing bore fit is recommended to eliminate creep while accommodating normal thermal gradient expansion.
As standard production, CHG Bearing subjects 28.91*30.2 to precision bainite or martensite quenching, offering dimensional stability up to 120°C (248°F). For high-heat processing equipment, CHG Bearing also supplies custom S0 (150°C), S1 (200°C), or S2 (250°C) stabilization heat treatments upon request to prevent residual austenite transformation.
