Radial Needle Roller Bearing Assembly K Series Needle Bearing Cage K15X21X21. High-Quality Material: Made of high-quality Baosteel with smooth surface and corrosion resistance. High Speed and Low Noise: Designed for high-speed operation with low noise and uniform rotational speed. High Load Resistance: Capable of withstanding high loads, suitable for demanding occasions. Long Service Life: Features high accuracy and durability to avoid repeated disassembly and maintenance. Cost-Effective Design: Saves costs on difficult-to-disassemble equipment by reducing maintenance needs. Comprehensive Size Range: Available in multiple models with bore sizes from 8 to 12 mm and varying dimensions. Single Row Structure: Single row radial bearing design with both inner and outer rings. OEM and ODM Services: Customization available for model numbers, weights, and driving torque.