Manufactured by CHG Bearing, the X4 is a precision Deep Groove Ball Bearings（618 / 619 SERIES）. Key dimensional parameters include a 4 mm bore diameter, a 9 mm outer diameter, and a 2.5 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.
X4 - Deep Groove Ball Bearings（618 / 619 SERIES）
Technical Specifications
| Overview | |
|---|---|
| Part Number | X4 |
| Brand | CHG® |
| Characteristics | |
| Bearing Type | Deep Groove Ball Bearing |
| Seal Type | Open / Contact Seal Options |
| Load Direction | Radial |
| Row Configuration | Single Row |
| Dimensions | |
| Bore Diameter (d) | 4 mm |
| Width (B) | 2.5 mm |
| Outer Diameter (D) | 9 mm |
| Bore Diameter Tolerance | -0.004-0 mm |
| Outside Diameter Tolerance | -0.004-0 mm |
| Width Tolerance | -0.04-0 mm |
| Performance | |
| Basic Dynamic Radial Load Rating Cr (kN) | 0.554 kN |
| Basic Static Radial Load Rating C0r (kN) | 0.201 kN |
| Material | |
| Mass (kg) | 0.001 kg |
| Ring Material | Stainless Steel |
| Cage Material | Polyimide |
| Ball Material | Stainless Steel |
| Operating Temperature Range (°C) | -50 to +100 °C |
| Precision Class | P4 |
| Radial Internal Clearance | 0.002-0.013 mm |
X4 9 mm 4 mm 2.5 mm Frequently Asked Questions about X4 Deep Groove Ball Bearings（618 / 619 SERIES）
Find key technical answers regarding dimensions, specifications, and replacement options for this model.
Standard batches of CHG Bearing X4 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.
Beyond standard alloy steel, CHG Bearing can customize the X4 Deep Groove Ball Bearings（618 / 619 SERIES） 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.
The CHG Bearing X4 is rated for limiting speeds up to standard rated RPM under forced oil-mist or circulating oil lubrication regimes. When lubricated with factory-filled synthetic high-speed grease, safe continuous velocity is maintained at approximately 75% to 85% of the maximum nominal limit, preventing thermal runaway.
In its sealed configuration (Open / Contact Seal Options), CHG Bearing pre-charges X4 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.
