The Difference Between Shot Blasting Machine and Sand Blasting Machine

Ⅰ. The principle of sand blasting machine and shot blasting machine

Shot blasting machine: The small steel shot or small iron shot is thrown out by the high-speed rotating impeller, and hits the surface of the part at a high speed, so the oxide layer on the surface of the part can be removed. At the same time, the steel shot or iron shot hits the surface of the part at a high speed, causing the lattice distortion on the surface of the part to increase the surface hardness. It is a method of cleaning the surface of the part. Shot blasting is often used to clean the surface of the casting or strengthen the surface of the part. Generally, shot blasting is used for regular shapes, etc., and several blasting heads are together up and down, left and right, with high efficiency and little pollution.

Sandblasting machine: Using compressed air as the power to form a high-speed jet beam, spray the spray material to the surface of the workpiece to be treated at a high speed, so that the mechanical properties of the outer surface of the workpiece surface change. There are many types of sandblasting machines, but the ultimate goal is to improve the fatigue resistance of the workpiece, which is also conducive to the leveling and decoration of the paint, remove impurities, variegated colors and oxide layers on the surface, and roughen the surface of the medium, at the same time, to eliminate the residual stress of the workpiece and improve the surface hardness of the substrate. 

Ⅱ. The difference between sand blasting machine and shot blasting machine

1. Sand blasting uses compressed air as the power, and the compressed air impacts the surface of the workpiece with sand (corundum, etc.); the shot blasting machine uses an electric high-speed impeller to project steel shot to impact the surface of the workpiece.

2. The materials used on the surface of the impact workpiece are different. The sand blasting adopts high-hardness wear-resistant materials such as corundum and emery, and the shot blasting machine adopts special steel sand of various special materials and shapes (called shot blasting).

3. The surface hardness obtained by the sand blasting machine and the shot blasting machine is different, and the shot blasting has a surface hardening effect.

4. Shot blasting and sand blasting are both surface treatments, but it does not mean that only castings are shot blasted.

5. The main function of sandblasting is to remove rust and scale on the surface, such as parts after heat treatment, while the shot blasting machine has more functions, not only including rust removal and surface scale removal, but also to improve surface roughness, remove the machining burrs of the parts, eliminate the internal stress of the parts, reduce the deformation of the parts after heat treatment, and improve the wear resistance and pressure capacity of the parts surface.

6. Sand blasting is mainly manual operation, while shot blasting is mostly automated and semi-automated.

7. The steel shot and iron shot used by the shot blasting machine are not actually shot in the real sense. To be precise, it is a small steel wire or a small steel rod. The so-called sandblasted sand is just river sand, which has nothing to do with construction. The two are the same, but the sandblasting is screened, contains less mud, and has different particle size specifications.