Manufactured by CHG Bearing, the 21*39 is a precision Cylindrical 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.
21*39 - Cylindrical Rollers
Technical Specifications
| Overview | |
|---|---|
| Part Number | 21*39 |
| Brand | CHG® |
| Product Type | Cylindrical Roller |
| Dimensions | |
| Roller Diameter, Dw | 21 mm |
| Roller Length, Lw | 39 mm |
| Center Recess Diameter | 9 mm |
| Through-hole Diameter | - mm |
| Center Recess Depth | 1 mm |
| Dimensional & Geometrical Accuracy | |
| Roller Diameter Tolerance | -0.02-0.005 mm |
| Roller Length Tolerance | -0.02 to 0 mm |
| Through-hole Runout | - mm |
| End-face Runout | 0.006 mm |
| Diameter Variation Between Ends | 0.002 mm |
| Roundness | 0.001 mm |
| Ovality | 0.001 mm |
| Surface Finish | |
| Outside Diameter Surface Roughness, Ra (µm) | 0.125 µm |
| End-face Surface Roughness, Ra (µm) | 0.2 µm |
| Chamfer Geometry | |
| Axial Chamfer | 0.8 mm |
| Axial Chamfer Tolerance | -0.3 to +0.3 mm |
| Radial Chamfer | 0.8 mm |
| Radial Chamfer Tolerance | -0.3 to +0.3 mm |
21*39 21 mm 39 mm Frequently Asked Questions about 21*39 Cylindrical Rollers
Find key technical answers regarding dimensions, specifications, and replacement options for this model.
To ensure optimum performance of CHG Bearing 21*39 Cylindrical 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.
Sourcing 21*39 directly from CHG Bearing eliminates intermediate brokerage markups while granting you factory-direct engineering backup, rigorous ISO-certified quality assurance, competitive volume wholesale pricing, and dependable supply chain stability for Cylindrical Rollers.
Quality starts with raw material selection: CHG Bearing crafts 21*39 inner and outer rings from high-purity High-Quality Chrome Steel (GCr15/100Cr6). Our raw billets undergo vacuum degassing and secondary ESR (electroslag remelting) processes to drastically eliminate non-metallic sulfide and oxide inclusions, elevating subsurface contact fatigue resistance.
Model 21*39 is manufactured by CHG Bearing in standard Normal clearance (CN) for ambient temperature transmission, and C3 or C4 clearance for heavy duty applications. C3 clearance compensates for radial shrinkage caused by tight shaft press-fits (bore mm) and steep thermal gradients between inner and outer rings.
