Pulleys are disc-shaped mechanical components that change the direction of ropes, wires, and belts while adjusting tension. In manufacturing, they serve as essential power transmission parts for lifting and moving heavy loads in cranes, hoists, conveyor systems, and various material handling equipment. Materials include cast iron, steel, aluminum, and resin, with bearing-integrated, fixed, and movable types selected according to application. They provide directional force conversion and mechanical advantage in overhead cranes, gantry cranes, jib crane hoisting devices, and production line conveyor systems, contributing to improved work efficiency and safety assurance.