The wire ropes commonly used for cranes include phosphating coated wire ropes, galvanized wire ropes and stainless steel wire ropes, which are used in atmospheric environment. The manganese phosphating coated steel wire rope produced by patented technology has the longest service life. At present, the fatigue test data show that the fatigue life of phosphating coated steel wire rope is about 3-4 times that of smooth steel wire rope with the same structure (under comparable conditions in laboratory), which is the reason why the service life of steel wire rope is greatly prolonged. It has far exceeded the imported steel wire rope, and the hot dip galvanized-phosphating double-coated steel wire rope is preferred for reference only.