​The structure of steel shot is tight and the particle size is uniform. Treating the surface of metal workpiece with steel shot can increase the surface pressure of metal workpiece and improve the fatigue resistance of the workpiece. The use of steel shot processing metal workpiece surface has the characteristics of fast cleaning speed, steel shot and steel grit have appropriate hardness, with good resilience and complex shape of the workpiece can be uniformly and quickly cleaned, shorten the surface treatment time, improve the work efficiency, is a good surface treatment material