The R8 bearing is one of the larger models within the Imperial miniature series, featuring an inner diameter of 12.7 mm (0.5 inches). This bearing is specifically engineered for micro- and small-scale machinery that requires the capacity to bear substantial loads while operating in complex environments. Constructed entirely from high-quality bearing steel, it achieves superior dynamic load limits through the optimization of steel ball diameters and raceway fill ratios.
Bearing Features
Characterized by a robust physical profile, its inner and outer rings—as well as its steel balls—undergo rigorous hardness testing and precision sorting, thereby representing the highest standard of durability within the Imperial miniature series.
This product serves as a critical structural component in heavy-duty power tools, mechanical joints, high-performance model aircraft motors, and precision assemblies within certain agricultural machinery. In these high-intensity applications, the R8 bearing functions not merely to support the rotating shaft, but also to act as a buffer against vibration and a safeguard against mechanical wear. By incorporating low-noise lubricants and precision sealing mechanisms, the bearing effectively reduces the overall operational noise levels of the equipment—thereby enhancing the quality of the finished machine—while simultaneously ensuring the delivery of high-output power.
Technical Specifications
| Bearing Reference | Boundary Diameters | Basic Dynamic | Basic Static | Limiting Speeds | ||||||||||||||||||
| Flange | Open | Shield | d inch |
d mm |
D inch |
D mm |
Df inch |
Df mm |
B inch |
B mm |
Bf inch |
Bf mm |
B1 inch |
B1 mm |
Bf1 inch |
Bf1 mm |
rsmin inch |
rsmin mm |
Cr kN |
Cor kN |
Grease | Oil |
| - | R8 | ZZ | 0.5 | 12.7 | 1.125 | 28.575 | 1.2252 | 31.12 | 0.25 | 6.35 | 0.062 | 1.575 | 0.3125 | 7.938 | 0.062 | 1.575 | 0.0157 | 0.4 | 5.11 | 2.41 | 1.6 | 1.8 |

Jiangsu Yinghong Transmission Technology Co., Ltd. (YHU) was established in 2024 through the joint investment of Dongguan Yinghong, Linqing Boshuo, and Yancheng Jiwei. As a group-based enterprise specializing in the research, development, manufacturing, and service of transmission products, we leverage extensive industry experience and strong technical expertise to provide reliable, energy-efficient transmission solutions for customers worldwide.
The company covers more than 70 mu of land and operates nearly 10,000 square meters of manufacturing facilities. As a professional manufacturer of precision special bearings in China, we have introduced advanced Japanese precision manufacturing technology and equipped our facility with automated production lines and high-precision testing equipment. A comprehensive quality management system ensures consistent product quality and reliable performance.
As a National High-Tech Enterprise, Yinghong holds multiple invention and utility model patents and has obtained internationally recognized certifications including IATF 16949, RoHS, CE, and SGS. These certifications enable us to meet diverse customer requirements and provide effective solutions for demanding applications and complex technical challenges.
We specialize in the production of high-precision deep groove ball bearings and custom non-standard bearings under our registered trademark, “YHU”. Our main products include bearing steel bearings, stainless steel bearings, ceramic bearings, and plastic bearings.
YHU bearings are designed to deliver low noise, low vibration, low friction, high precision, great sealing performance, and high-speed operation. They also offer self-lubrication, corrosion resistance, rust resistance, acid and alkali resistance, chemical resistance, electrical insulation, non-magnetic properties, high-temperature resistance, low-temperature adaptability, and long service life, making them suitable for demanding operating environments.
Our bearings and bearing assemblies are widely used in electric motors, power tools, pneumatic tools, robotics, drones, household appliances, precision instruments, semiconductor equipment, medical devices, marine equipment, aerospace applications, financial equipment, textile machinery, fishing equipment, and a wide range of specialized industrial equipment.
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