Nuts are a common type of fastener, classified as a mechanical fastening device, widely used in fields such as mechanical manufacturing. A nut is composed of a hollow cylinder and an internal threaded boss that corresponds to the screw thread. It connects to another mating part through the rotation of a screw, achieving a fixed effect. Therefore, nuts are part of the fastener category, serving functions of fixation, connection, and support. They are extensively used in various industries including automotive, railway, aviation, shipping, electronics, appliances, construction, and furniture.