On the premise of meeting the surface roughness requirements, larger steel shots should be used as much as possible to improve the cleaning efficiency.

It is best to use graded steel shots. Graded steel shots are composed of 50% nominal size steel shots and gradually smaller steel shots, taking into account the impact force and coverage, and can obtain the highest cleaning efficiency and lower surface roughness (compared with a single-grain steel Compared to pills).

In the production process, each steel shot is a process of continuous wear and tear, so the particle size of each steel shot is constantly changing. Since the hot spot changes with the particle size of the steel shot, in order to ensure that the thermal particle size / ram distribution gradually approaches the normal curve. If too much feed is added at one time, the surface of the casting will become rough immediately; if no feed is added for a long time, although the surface quality of the casting is improved, the cleaning efficiency will be greatly reduced.