It is one of the most common lifting tools in lifting machinery. The hook is often suspended on the wire rope of the hoisting mechanism with the help of components such as pulley blocks. Hooks can be divided into single hooks and double hooks according to their shapes; and they can be divided into forged hooks and laminated hooks according to manufacturing methods. Single hooks are simple to manufacture and convenient to use, but their stress conditions are not good. They are mostly used in working situations where the lifting capacity is below 80 tons. When the lifting capacity is large, double hooks with symmetrical stress are often adopted. Laminated hooks are formed by riveting several pieces of cut and shaped steel plates. When individual plates have cracks, the entire hook will not be damaged, so it has good safety performance. However, it has a relatively large self-weight and is mostly used in cranes with large lifting capacities or for lifting molten steel ladles. Hooks are often subject to impacts during the operation process, so high-quality carbon steel with good toughness must be used for manufacturing. The classification of hooks is extremely extensive and generally includes shackles, lifting rings, circular rings, pear-shaped rings, long lifting rings, combined lifting rings, S-hooks, nose hooks, American hooks, ram's horn hooks, eye-shaped sliding hooks, lifting ring screws with safety clips, chain shackles. They have the characteristics of being unique, novel, high-quality and safe, and are suitable for factories, mines, petroleum, chemical industries and ship docks, etc. They ensure safety, and the quality safety factor can reach 3 times the static load. The lifting capacity ranges from 5 tons to 150 tons.