Important performance indicators in the hook group

As a important mechanical device in the lifting equipment, the hook group completes the lifting work of the heavy objects by means of components such as pulley blocks. The hook group is in use, because there are single hooks and double hooks, and depending on the application and the scope of use, the hook group also has different material choices. The hook set is in use and its performance indicators are as follows:

The hook material can be made of 20 high-quality carbon steel or special material for hooks DG20Mn, DG34CrMo, etc. It is strictly forbidden to use casting hook. The material of the hook is generally applied to A3, C3 ordinary carbon steel, or 16Mn low alloy steel.

The purchase of hooks should be accompanied by technical documents such as the manufacturer's certificate of conformity; important departments should purchase hooks such as railways and ports, and the hooks must be strictly tested (inspection). It is possible to select two suitable positions at the shortest distance of the hook opening to print a mark that is not easy to wear, and measure the distance of the mark as a basis for detecting whether the opening degree changes during use.

If the hook group is subjected to the overload test for a long period of time, the scrapping process is required, and the fully-closed welding process is not allowed between the hook and the lamination of the hook group, but the welding can be performed. Hooks shall not have defects affecting the safe use performance; hook defects shall not be welded; the surface of the hook shall be smooth, and there shall be no defects such as cracks, folds, sharp angles, burrs, peeling, and over-burning.

The hook and hook pieces of the hook group are riveted by the countersunk rivets, and the high-stress bending parts where the hooks of the hooks are in contact with the lifting points of the lifting objects are not connected by rivets. The longitudinal axis of the hook and hook of the hook group must be in the rolling direction of the steel plate, and the hook pieces are not allowed to be spliced.