Using compressed air as the power to form a high-speed stream, the stream contains ‘media' (emery, steel sand, Alumina powder、Quartz sand, Silicon carbide, etc), the stream is sprayed onto the surface of the parts being worked with. Due to the impact of the ‘media', the surface of the parts obtains a certain degree of roughness.

Sandblasting is widely used as after-treatment of CNC, Casting, injection process, etc. It can be used to remove rust, cover tool mark, increase total surface area for other surface treatment, deburring and smooth sharp edge. It can be applied to all metal parts and most of the hard plastic parts. Obviously, smaller graininess ‘media' creates a finer and smoother surface while bigger graininess ‘media' creates a rougher surface. Wet sandblasting ("media" contains liquid) also result in a smoother and finer surface on the workpiece than dry sandblasting. With long enough spray time, it could ‘eat up' some size, but most of sandblasting is handled by labors so the level of ‘eat-up' is controllable. All in all, sandblasting makes the workpiece's surface looks muted.