The Koyo 5210 Double Row Ball Bearing is built from premium 52100 steel for strength and durability in demanding applications. With a 50 mm (1.9685 in) round bore, riveted steel cage, and open closure design, it features C0 internal clearance for stable operation. Its double-row construction provides enhanced load capacity, making it ideal for supporting high radial and moderate axial loads while ensuring reliable performance in heavy-duty machinery.