What do the suffixes of your precision bearing models mean (e.g., ZZ/2RS/C3/P5)?

The suffixes attached to our precision miniature bearing models are standardized markings defined according to international ISO standards, which clearly indicate sealing structure, internal clearance, precision tolerance, and application performance. Understanding these suffixes helps you select the most suitable bearing for your equipment, speed, environment, and service life requirements.

ZZ indicates double-sided metal shields. This structure effectively blocks dust, fine particles, and mechanical impurities from entering the bearing interior. It is non-contact type, so it supports relatively high rotating speeds and maintains stable torque. However, it cannot fully prevent moisture, oil, or liquid penetration. ZZ bearings are widely used in general industrial applications, small motors, power tools, fans, and household appliances where clean working conditions exist.

2RS stands for double-sided rubber contact seals. Compared with ZZ, it provides a much higher level of protection. The rubber lip fits closely with the inner ring, effectively sealing lubricating grease inside while blocking dust, moisture, oil mist, and mild corrosive substances. This structure extends service life significantly in harsh environments. It is more suitable for humid, dusty, or outdoor equipment, but may slightly increase rotational resistance, making it ideal for low-to-medium speed applications.

C3 represents radial internal clearance greater than the standard CN clearance. Bearings with C3 clearance are designed to avoid excessive friction, jamming, or overheating under high-speed rotation, elevated temperatures, or minor shaft expansion. They improve heat dissipation and reliability, commonly used in high-speed motors, transmission components, textile machinery, and equipment that runs continuously for a long time.

P5 refers to precision grade ISO P5, also known as ABEC 5. It offers significantly higher dimensional accuracy, rotation accuracy, and runout control than the standard P0 grade. Bearings marked P5 feature low noise, stable rotation, small axial and radial runout, and strong high-speed stability. They are mainly used in precision instruments, automation equipment, CNC accessories, medical devices, and high-performance transmission systems requiring precision control.

Together, these suffixes define the bearing’s performance and application scope. We also provide other common suffixes such as Z (single shield), RS (single seal), C4 (larger clearance), and P6 (intermediate precision) to meet diverse industrial needs.