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608 Deep Groove Ball Bearing 8x22x7mm
The 608 bearing is the standard 8mm-bore deep groove ball bearing in the ISO 600 series: 22mm OD, 7mm width, 2.89 kN dynamic load. It bridges the gap between the 607 bearing (7mm bore, 19mm OD) and the 609 bearing (9mm bore, 24mm OD). When a design calls for an 8mm shaft and the housing bore is budgeted at 22mm, the 608 bearing is the catalog answer.
Key Specifications
- Sealing: Open, ZZ (metal shields), or 2RS (rubber seals). ZZ reaches full speed rating with non-contact protection.
- Speed and Load: 34,000 RPM (open) with 2.89 kN dynamic and 1.37 kN static load. 2RS configuration rated to 26,000 RPM.
- Radial Fit: 8mm bore, 22mm OD, 7mm width. 7mm radial cross-section; the standard 8mm-bore bearing in the 600 series.
- Temperature Range: -20C to 120C with standard polyurea grease. 150C peak available with high-temperature lubricant.
- Precision: Standard ABEC-1. ABEC-3 and ABEC-5 available for tighter bore and radial runout tolerances.
For any inquiries, please contact with our Supporting Team at sales@yuanhecd.com.
| Model | 608 |
| Type | Open / Shielded / Sealed |
| Bore (d) | 8 mm |
| OD (D) | 22 mm |
| Width (B) | 7 mm |
| Dynamic Load Cr | 2.89 kN |
| Static Load Cor | 1.37 kN |
| Max Speed | 34,000 RPM (open) / 26,000 RPM (2RS) |
| ABEC | ABEC-3 |
| Temperature Range | -20 to 120 deg C |
| Material | GCr15 (AISI 52100 equivalent) |
| Shield / Seal Material | SPCC steel (ZZ) / NBR rubber (2RS) |
| Lubrication | Grease |
Bore x OD x Width
8 x 22 x 7 mm
Dynamic Load Cr
2.89 kN
Static Load Cor
1.37 kN
Max Speed
34,000 RPM
Sealing
Open / ZZ / 2RS
Precision
ABEC-3
Shielding and Lubrication
The 608 bearing ships in three sealing configurations. Open (no suffix) suits oil-bath and oil-mist lubricated housings where the lubrication system handles contamination control. ZZ shields use non-contact pressed-steel covers retained in the outer ring; they trap factory grease while adding zero friction, reaching the full 34,000 RPM rating. 2RS seals use nitrile rubber lips contacting the inner ring groove, blocking moisture and particulates at a reduced speed ceiling of approximately 26,000 RPM. The 2RS version ships pre-packed with polyurea grease and needs no field relubrication.
At 7mm width and 22mm OD, the 608 bearing has a radial cross-section of 7mm. This is enough section height that 2RS seal lip drag accounts for roughly 5 to 7 percent of drive torque at 26,000 RPM in fractional-horsepower motors. ZZ shields reduce this to near zero. For enclosed gearboxes and pump housings where the oil system provides contamination control, open bearings run coolest at maximum speed. For motors exposed to factory dust or outdoor moisture, 2RS seals extend service intervals.
Performance
The 608 bearing carries 2.89 kN dynamic and 1.37 kN static load at 34,000 RPM in open configuration. This places it at the center of the narrow 600 series. The step down to the 607 bearing (7x19x6mm, 2.34 kN) costs 0.55 kN of load capacity and 1mm of bore. The step up to the 609 bearing (9x24x7mm, 3.35 kN) gains 0.46 kN for 1mm more bore and 2mm more OD. The 608 bearing weighs approximately 12g per unit.
Compared to the 628 bearing (8x24x8mm, 3.35 kN dynamic), the 608 bearing gives up 0.46 kN of capacity but saves 2mm in housing diameter and 1mm in width. For a design where the 22mm OD fits in a standard housing bore and the load is within 2.89 kN, specifying the 608 bearing avoids the larger 628 bearing OD. When the load pushes past 2.89 kN or the housing can accept 24mm, the 628 bearing is the next catalog step. For OEM deep groove ball bearing selection, the 608 bearing represents the most common starting point in the 8mm-bore family.
OEM and Customization
Yuanhe manufactures the 608 bearing to customer specifications beyond catalog dimensions. Common OEM requests for the 8mm-bore series include C3 radial clearance for electric motor thermal expansion, low-noise grease fills for office equipment and home appliance applications, and 440C stainless steel rings and balls for food-grade and washdown environments. Non-standard bore tolerances and custom cage materials (brass, polyamide, or steel) are available against drawing. For OEM orders, send bearing dimensions or part number for a quote.
Applications
Fractional-horsepower electric motors
Office equipment fans and copier rollers
Small pump and compressor shafts
Conveyor pulley bearings
Packaging machine rollers
Small gearbox input and output shafts
Textile spinning rotors
HVAC fan motor assemblies
Frequently Asked Questions
What is the difference between 608 bearing and 628 bearing? +
Both have an 8mm bore. The 608 bearing has a 22mm OD, 7mm width, and 2.89 kN dynamic load. The 628 bearing steps up to a 24mm OD, 8mm width, and 3.35 kN dynamic load. The 628 bearing delivers 16 percent more load capacity but requires 2mm more housing diameter and 1mm more axial space. Specify 608 bearing when the 22mm OD fits the housing. Specify 628 bearing when the load exceeds 2.89 kN or a wider bearing is preferred for stability.
Can the 608 bearing handle radial and axial loads simultaneously? +
As a deep groove ball bearing, the 608 bearing handles combined loading with axial capacity at roughly 25 to 30 percent of the unused radial capacity. With 2.89 kN dynamic radial rating, pure axial capacity is approximately 0.72 kN. For sustained combined loading where axial force exceeds 30 percent of radial force, consider angular contact or paired mounting. Contact Yuanhe with your load data for sizing assistance.
What grease options are available for the 608 2RS bearing? +
Standard fill is polyurea-thickened mineral grease, 100 cSt at 40C, rated -20C to 120C. Custom options include filtered low-noise lithium grease for office and home appliance applications, wide-temperature synthetic grease (PAO base) for -40C to 150C operation, and food-grade H1 grease for incidental food contact in processing equipment. Fill quantity is 25 to 35 percent of free internal volume. Specify grease type at the RFQ stage. Minimum order quantity applies for custom fills.
What is the expected service life of a 608 bearing under rated load? +
Basic rating life (L10) at the 2.89 kN dynamic load and 34,000 RPM is approximately 500 hours for 90 percent survival probability. At half the rated load (1.45 kN), L10 life extends to roughly 4,000 hours. Actual service life depends on lubrication condition, contamination level, mounting accuracy, and operating temperature. These are catalog calculations; real-world life varies with application conditions.
