617/8 678 Minature Deep Groove Ball Bearings 8mm X 12mm X 2.5mm
Thin Section Robot Bearings
8mm Bore 678 617/8 Minature Deep Groove Ball Bearing 8 X12X2.5mm
Single Row Open Type Rolling Radial Ball Bearing Thin Section Robot
Bearing High Performance Bearing
The 678 miniature deep groove ball bearing, with dimensions of 7mm
inner diameter × 11mm outer diameter × 3mm width, is renowned for
its compact size, high-speed capability, and low noise
characteristics.
Bearing Number | Boundary Dimensions(mm) | Basic Load Rating(N) | Limiting Speed(rpm) | Reference(kg)
Weight |
| Inner Diameter | Outer Diameter | Width | Chamfer | Dynamic | Static | Grease | Oil |
| d | D | B | B1 | r(min) | Cr | Cor | Non-contact | Wt ≈ |
| 617/3 | ZZ | | 3 | 6 | 2 | 2.5 | 0.1 | 242 | 94 | 60000 | 71000 | 0.00020 |
| 617/4 | ZZ | | 4 | 7 | 2 | 2.5 | 0.1 | 222 | 88 | 54000 | 63000 | 0.00028 |
| 617/5 | ZZ | | 5 | 8 | 2 | 2.5 | 0.1 | 217 | 91 | 49000 | 57000 | 0.00032 |
| 617/6 | ZZ | | 6 | 10 | 2.5 | 3 | 0.1 | 465 | 196 | 43000 | 51000 | 0.00065 |
| 617/7 | ZZ | | 7 | 11 | 2.5 | 3 | 0.1 | 555 | 269 | 40000 | 47000 | 0.00067 |
| 617/8 | ZZ | | 8 | 12 | 2.5 | 3.5 | 0.1 | 515 | 252 | 38000 | 45000 | 0.00075 |
| 617/9 | ZZ | | 9 | 14 | 3 | 4.5 | 0.1 | 920 | 465 | 36000 | 42000 | 0.00140 |
678 Ball Bearings 8X12X2.5mm Specifications & Dimensions
| Universal | 678 |
| Type | Deep Groove Ball |
| Inner/Outer Ring/ Ball Material | Chrome Steel |
| Cage Material | Steel/Nylon |
| CageType | Punching |
| Precision | P0,P6 |
| Inner Dimension d(Ø)(mm) | 8 |
| Outer Dimension D(Ø)(mm) | 12 |
| Width B (or T)(mm) | 2.5 |
| Lubrication | Grease or oil |
| Load Direction | Radial |
| Specifications/Environment | Standard |
| Number of Raceway Ring Rows | Single Track |
| Size Standards | Metric Series |
The 678 miniature deep groove ball bearing is widely used across
various specialized fields due to its compact size and high
precision. Application areas include:
1. Precision Machinery and Automation Equipment
Suitable for transmission systems and rotating mechanisms, ensuring
precise movement and long operational life in equipment.
2. Micro Motors and Stepper Motors
Acts as a core component supporting the rotor or shaft, ensuring
stable motor operation. Commonly found in electric tools, household
appliances (such as air conditioner motors and washing machine
motors), and other devices requiring consistent performance.
3. Electronic Products and Instrumentation
Utilized in hard disk drives, sensors, optical instruments, and
other devices that require low noise and high-precision control,
contributing to their smooth and accurate functioning.
4. Automotive Industry
Potentially used in small transmission components or auxiliary
systems such as seat adjustment mechanisms and steering systems.
Particularly valuable in scenarios where compact design is
essential.
5. Industrial Support and Aftermarket
Serves as a standard part for maintenance and replacement in
mechanical transmission products, meeting the needs of aftermarket
support for imported bearings.
