R4-ZZ Deep Groove Ball Bearing | High-Precision Imperial Series | 6.35×15.875×4.978 mm

The R155-ZZ is a precision-engineered imperial miniature ball bearing specifically developed for applications requiring a 5/32-inch shaft interface. Featuring a dual-shielded ("ZZ") construction, this model provides a robust defense against dust and debris, ensuring the internal raceways remain clean and well-lubricated. This enclosed design makes the R155-ZZ an ideal, "set-and-forget" component for high-speed micro-motors, precision encoders, and small-scale mechanical linkages where reliability and low-maintenance operation are paramount.

The R155-2RS is a high-performance miniature imperial ball bearing engineered for specialized applications requiring a contaminant-free environment within a compact footprint. Featuring dual-sided Nitrile Rubber (2RS) contact seals, this bearing provides an exceptional barrier against dust, moisture, and fine particulates while ensuring excellent grease retention. Designed for 5/32-inch shafts, the R155-2RS is a vital component for high-precision instruments and micro-mechanisms where long-term reliability and zero maintenance are paramount.

The R2A-ZZ is a specialized imperial miniature ball bearing designed for applications that require a small 1/8-inch bore but demand higher load-bearing stability than standard micro-bearings. Featuring an exceptionally robust 1/2-inch outer diameter relative to its bore size, the R2A-ZZ offers enhanced structural rigidity and radial strength. The double-shielded ("ZZ") configuration utilizes two non-contact metal plates to retain high-performance lubricant while acting as a barrier against dust and environmental contaminants, making it a reliable choice for high-speed, maintenance-free operation.

The R2-6-ZZ is a high-performance miniature imperial ball bearing engineered for applications that require a balance of compact sizing and enhanced structural rigidity. Featuring dual metal shields (ZZ), this bearing is designed to retain high-speed lubricant while providing a robust physical barrier against larger contaminants and debris. With its 1/8-inch bore and a wider-profile 5/32-inch width, the R2-6-ZZ offers superior radial load support compared to ultra-slim variants, making it ideal for precision motors and mechanical drive systems.

The R2-6-2RS is a high-performance imperial miniature bearing specifically engineered for environments where exposure to moisture, dust, or fine particulates is a concern. Featuring a dual-contact rubber seal ("2RS") design, this bearing provides a superior airtight enclosure compared to metal shields. The synthetic rubber seals are reinforced with steel inserts, ensuring that the factory-applied grease remains securely inside the raceways while effectively blocking external contaminants. With a standard 1/8-inch bore and a 3/8-inch outer diameter, the R2-6-2RS is the ideal choice for outdoor equipment, small power tools, and high-precision mechanical assemblies operating in demanding conditions.

The R2-5-ZZ is a precision-engineered, inch-series miniature deep groove ball bearing designed for applications where rotational stability and radial clearance control are paramount. With a 1/8" bore diameter, this model is slightly more robust than the ultra-micro series, offering a balanced power-to-size ratio. It is equipped with dual metallic shields (ZZ) that provide a physical barrier against workplace debris while maintaining a non-contact interface with the inner ring to prevent friction-induced heat. This specialized construction ensures the R2-5-ZZ remains the preferred choice for high-speed micro-motors and sensitive transmission systems.

The R2-5-2RS is a highly resilient inch-series miniature deep groove ball bearing engineered to deliver reliable rotation in environments prone to dust and moisture. Featuring a standard 1/8" inner diameter, this micro bearing is equipped with dual contact rubber seals (2RS) crafted from durable NBR (Nitrile Butadiene Rubber). Unlike standard metal shields, these contact seals create a physical barrier against external particle ingress and fluid splashes. This heavily shielded architecture effectively locks in premium factory grease while preventing abrasive contaminants from reaching the raceways, making the R2-5-2RS an essential component for demanding outdoor applications and exposed micro-mechanisms.

The R2-5 Open is a precision-engineered, inch-dimensional miniature deep groove ball bearing developed specifically for applications demanding absolute minimum rotational resistance. With a standard 1/8" bore diameter, this bearing utilizes an entirely unshielded (open) architecture. By eliminating the physical barriers of shields or rubber seals, the R2-5 Open achieves a zero-contact environment that eradicates frictional drag. This design is highly favored for mechanisms housed within clean, enclosed environments or oil-bath systems, where maximum RPM and rapid heat dissipation are critical for system performance.