When selecting the sling specification, the size, weight, shape of the load to be lifted, as well as the service mode coefficient affected jointly by the lifting method to be used must be included in the calculation. The requirements for the ultimate working force given must be taken into account. At the same time, the working environment and the type of load must be considered.

Slings are ropes made of steel wire ropes or synthetic fibers for hoisting. It is also called jack rope or jack rope or rope buckle. It is used to connect the crane hook and the hoisted equipment.