Blast cleaning may be defined as a mechanical pre-treatment process in which a suitable stream of solid particles is propelled with sufficient velocity against a work surface to cause a cleaning or abrading action when it comes in contact with the workpiece. Blast cleaning may be employed for a variety of purposes. It is a well-established method for removing sand from castings and burrs or scale from forgings, mill products, or heat treated parts; to promote machinability; and to minimize the possibility of interference in actual operation. In addition to this use, blast cleaning also produces a suitable surface for downstream industrial coatings. All these objectives are often accomplished in the one operation. As a general understanding, this document pertains to blast cleaning only. Any reference to shot peening or other processes is only to explain a context or concept related to blast cleaning.