Manufactured by CHG Bearing, the 45*78 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.

45*78 - Cylindrical Rollers
Technical Specifications
| Overview | |
|---|---|
| Part Number | 45*78 |
| Brand | CHG® |
| Product Type | Cylindrical Roller |
| Dimensions | |
| Roller Diameter, Dw | 45 mm |
| Roller Length, Lw | 78 mm |
| Center Recess Diameter | 20 mm |
| Through-hole Diameter | - mm |
| Center Recess Depth | 1.5 mm |
| Dimensional & Geometrical Accuracy | |
| Roller Diameter Tolerance | -0.015-0.003 mm |
| Roller Length Tolerance | -0.02 to -0.01 mm |
| Through-hole Runout | - mm |
| End-face Runout | 0.01 mm |
| Diameter Variation Between Ends | 0.002 mm |
| Roundness | 0.002 mm |
| Ovality | 0.002 mm |
| Surface Finish | |
| Outside Diameter Surface Roughness, Ra (µm) | 0.18 µm |
| End-face Surface Roughness, Ra (µm) | 0.25 µm |
| Chamfer Geometry | |
| Axial Chamfer | 1.5 mm |
| Axial Chamfer Tolerance | -0.2 to +0.2 mm |
| Radial Chamfer | 1.5 mm |
| Radial Chamfer Tolerance | -0.2 to +0.2 mm |
45*78 45 mm 78 mm Frequently Asked Questions about 45*78 Cylindrical Rollers
Find key technical answers regarding dimensions, specifications, and replacement options for this model.
Model 45*78 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.
To ensure optimum performance of CHG Bearing 45*78 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.
Engineered according to international ISO boundary plans, CHG Bearing supplies 45*78 with a precision bore diameter (d) of mm, an outside diameter (D) of mm, and a nominal ring width (B) of mm. This configuration yields an effective cross-sectional wall thickness of 0 mm and an envelope ratio (D/d) of 0, delivering compact rigidity for OEM machinery housings.
Each 45*78 produced in CHG Bearing manufacturing facilities features accurately profiled corner chamfers complying with DIN 5412 / ISO standard corner radii. When designing mating shafts and housing shoulders, machining an undercut or fillet radius strictly within the inner ring clearance limit ( mm bore side) ensures perfect planar contact without edge binding.
