Introduction to 628 Series Miniature Bearings:
The 628 series bearings are high-performance miniature bearings designed for precision and durability in demanding industrial environments. Known for their compact design and versatility, these bearings are ideal for applications requiring smooth operation, high rotational speeds, and low noise.

Key Features:
- Compact Design: Small dimensions (8mm bore, 24mm OD, 8mm width) suit space-constrained machinery.
- High-Speed Capability: Optimized for applications up to 30,000 RPM (grease-lubricated).
- Low Noise & Vibration: Precision-ground races and balls ensure quiet operation.
- Material Options: Chrome steel (standard) or stainless steel (corrosion-resistant).
- Versatile Sealing: Available in OPEN, ZZ (metal shields), or 2RS (rubber seals) configurations.
Typical Applications:
- Small Motors: Cooling fans, drone motors, and power tools.
- Medical Devices: Dental handpieces, lab equipment, and imaging systems.
- Office Equipment: Printers, scanners, and CNC spindle accessories.
- Robotics: Joints and actuators requiring precise motion control.
Comparison: 628 ZZ vs. 628 2RS vs. 628 OPEN
Feature | 628 ZZ | 628 2RS | 628 OPEN |
Sealing Type | Metal shields (both sides) | Rubber seals (both sides) | No sealing |
Protection Level | Dust resistance | Water/dust resistance | None |
Speed Rating | High (30,000 RPM) | Moderate (25,000 RPM) | Highest (35,000 RPM) |
Lubrication | Pre-greased | Pre-greased | Requires external grease |
Maintenance | Low | Low | Frequent relubrication |
Typical Use | Clean environments | Harsh/dirty conditions | High-speed, clean setups |
Shared Attributes:
- Dimensions: 8x24x8 mm (IDxODxWidth).
- Dynamic Load: ~1.3 kN; Static Load: ~0.5 kN.
- ABEC Rating: ABEC-1 (standard) or ABEC-3 (on request).
- Material: Chrome steel (GCR15) or stainless steel (AISI 440).
This series is widely used in miniature bearings markets due to its balance of performance and cost. For interchangeable options, the 628 bearing matches with MR84 (Japanese) or R-1240 (American) standards.

Technical Parameters of Power Tool Ball bearings:
Basic Bearing No. | Bore d | Outer Diameter D | Width W | Radius r | Basic Load Rating KN | Maximum Run out Speed | Weight Kg/pc |
Dynamic | Static | Grease | Oil |
mm | inch | mm | inch | mm | inch | mm | inch | C | CO | r/min | r/min |
604 | 4 | 0.1575 | 12 | 0.4724 | 4 | 0.1575 | 0.2 | 0.008 | 0.97 | 0.36 | 43000 | 51000 | 0.002 |
605 | 5 | 0.1969 | 14 | 0.5512 | 5 | 0.1969 | 0.2 | 0.008 | 1.33 | 0.505 | 39000 | 46000 | 0.0035 |
606 | 6 | 0.2362 | 17 | 0.6693 | 6 | 0.2362 | 0.3 | 0.012 | 2.24 | 0.91 | 28000 | 36000 | 0.008 |
607 | 7 | 0.2756 | 19 | 0.7480 | 6 | 0.2362 | 0.3 | 0.012 | 2.24 | 0.91 | 28000 | 36000 | 0.008 |
608 | 8 | 0.3149 | 22 | 0.8661 | 7 | 0.2756 | 0.3 | 0.012 | 3.35 | 1.4 | 26000 | 34000 | 0.012 |
609 | 9 | 0.3543 | 24 | 0.9449 | 7 | 0.2756 | 0.3 | 0.012 | 3.4 | 1.45 | 22000 | 30000 | 0.014 |
6000 | 10 | 0.3937 | 26 | 1.0236 | 8 | 0.3150 | 0.3 | 0.012 | 4.55 | 1.96 | 20000 | 28000 | 0.019 |
6001 | 12 | 0.4724 | 28 | 1.1024 | 8 | 0.3150 | 0.3 | 0.012 | 5.1 | 2.39 | 19000 | 26000 | 0.021 |
6002 | 15 | 0.5906 | 32 | 1.2598 | 9 | 0.3543 | 0.3 | 0.012 | 5.6 | 2.84 | 18000 | 24000 | 0.03 |
6003 | 17 | 0.6693 | 35 | 1.3780 | 10 | 0.3937 | 0.3 | 0.012 | 6.8 | 3.35 | 17000 | 22000 | 0.039 |
6004 | 20 | 0.7874 | 42 | 1.6535 | 12 | 0.4724 | 0.6 | 0.024 | 9.4 | 5.05 | 15000 | 19000 | 0.069 |
6005 | 25 | 0.9843 | 47 | 1.8504 | 12 | 0.4724 | 0.6 | 0.024 | 10.1 | 5.85 | 13000 | 17000 | 0.08 |
6006 | 30 | 1.1811 | 55 | 2.1654 | 13 | 0.5118 | 1.0 | 0.039 | 13.2 | 8.3 | 12000 | 15000 | 0.116 |
Applications of Power Tool Ball Bearings:
Customization:
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We can printing your brand (logo,artwork)on the shield or laser engraving your brand on the shield.
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We can custom your packaging according to your design.
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All copyright owned by clients and we promised don't disclose any information.
Packing and Shipping:
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The deep groove ball bearings will be securely packaged individually, or tube packing or packed as customization packing
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Shipping method is negotiable.