Rigid couplings are mechanical devices used to connect two shafts together, ensuring they rotate in unison without any relative movement. They are designed to transmit torque and maintain alignment between the shafts, making them ideal for applications where precision is crucial. Common materials for rigid couplings include steel and aluminum, which provide strength and durability. These couplings come in various designs, such as clamp, sleeve, and flanged types, each suited for different applications. Rigid couplings are often used in machinery, such as motors and gearboxes, where consistent performance and minimal backlash are essential for efficient operation.