A universal joint (U-joint) is a mechanical device used to transmit rotational motion between two shafts that are not aligned on the same axis. Capable of accommodating angular misalignment between shafts, it is essential in applications such as drive shafts, power take-off (PTO) shafts, and steering systems. The universal joint consists of a cross-shaped central component with needle roller bearings at each end, ensuring flexibility of movement and smooth rotation. These joints are widely used in automobiles, agricultural machinery, and various types of industrial equipment. By helping to absorb vibration, accommodate movement, and maintain torque transmission despite angular changes, they ensure efficient power delivery and durable, reliable performance under demanding operating conditions.