A screw jack is a lifting device that uses the principle of helical transmission to achieve mechanical lifting, and is used in fields such as automotive maintenance, construction engineering, and industrial manufacturing. It has a simple structure, strong load-bearing capacity, and high stability, making it suitable for situations where short-distance lifting heights are required. The working principle of the screw jack is based on the principle of helical transmission: 1. Rotating the handle drives the screw to rotate. 2. The screw engages with the fixed nut, and due to the inclined surface of the threads, the screw rises or descends while rotating. 3. The support block moves with the screw, achieving the lifting or lowering of the load.