These machines have a perpetual caterpillar made from perforated rubber belt or from steel flaps. Treated objects are put by a special filing contraction to caterpillar. When caterpillar moves its special shape causes treated objects to turn and roll, which causes the whole surface of the treated objects to be quality blasted in a jet of abrasive. These machines are used for shotblasting casts, forged and pressed parts, and remodelled cold or hot, of various complicated forms, springs, etc.
