In blast cleaning, various agents or blasting mediums are used for different types of cleaning and results. The hardness, sharpness, size and type of material defines the results of such cleaning in distinct ways. The most common materials are sand, steel, copper, glass, plastic and CO2 dry ice. The grain size can be from micron sized up to a millimetre or so.
The intended use may be roughening, descaling or derusting, degreasing, oxidized forging cleaning, paint and coating removal, polishing or surface hardening (shot peening). They are generally not effective for removing particulates, oils or greases; they are noisy, and have limited use on parts with irregular shapes and crevices.