The Cross Roller Bearing RA Series is a premium thin-wall bearing designed for high-precision rotational systems, renowned for its integrated structure, exceptional rigidity, and multi-directional load capacity. Widely used in industrial robots, precision machining centers, and medical equipment, this series stands out as a cost-effective alternative to THK RA/RA-C and IKO CRBS series, delivering superior performance in space-constrained environments.
At its core, the RA Series features cylindrical rollers arranged at 90° perpendicular angles, separated by high-quality spacers. This cross-roller design enables the bearing to simultaneously withstand radial loads, axial loads, and overturning moments—outperforming standard ball bearings with 3-5 times higher rigidity via line contact between rollers and raceways.

Engineered with an integrated inner and outer ring (non-separable) structure, the RA Series achieves ultra-thin profiles with widths ranging from 8mm to 13mm, reducing cross-sectional area by 43% and weight by 38% compared to traditional bearings. Rotation accuracy reaches P4/P2/USP grades, with repeat positioning error ≤±0.001mm, meeting micron-level motion control demands.

Pre-lubricated with high-performance lithium grease and optional non-contact RS seals, the RA Series ensures dust resistance and long-term maintenance-free operation. Crafted from GCr15 high-carbon chromium bearing steel with TN engineering plastic cages, it offers excellent wear resistance and corrosion resistance, extending service life in harsh industrial conditions.

Available in inner diameters from 20mm to 250mm, the RA Series suits diverse applications—from robot joints and manipulator rotary units to precision turntables and IC manufacturing equipment. Its low-friction design minimizes rotational torque, enabling smooth high-speed operation while maintaining stability, making it an indispensable component for advanced automation.