Shafts and spindles are fundamental components in mechanical systems, serving as the primary means of transmitting rotational motion and torque between different parts of machinery. Shafts are typically long, cylindrical rods that connect various mechanical elements, such as gears, pulleys, or wheels, enabling them to rotate in unison.

They are engineered to handle significant loads and stresses while maintaining precise alignment and smooth operation. Spindles, on the other hand, are similar but often smaller and designed to rotate within a specific assembly, such as in a motor or tool.