As a rule, the greater the pressure that can be exerted onto a part, either by equipment or the weight of the media, the greater the material removal. Therefore, some guidelines can be helpful for selecting media supplies for particular parts and applications. The most typical application of mass finishing equipment is to deburr parts en masse. The cheapest and fastest way to do this is to use the largest abrasive possible that still is small enough to reach all part areas without getting stuck. Unfortunately, finding the perfect abrasive size is not easy.
Different parts have different hardness, size, and finishing requirements.
An abrasive that works well on one part may not be able to achieve the desired end result on another part. Nonferrous or soft metals typically are not finished with the largest, coarsest abrasive, because the metal will have a rougher finish than it did before processing. Usually, the cheapest form of any abrasive product is a loose, random-shaped, naturally occurring mineral compound classified by screen sizes. Although this material commonly is used with blast finishing equipment, it is rarely used for mass finishing, because media that varies in size and shape is more likely to get stuck in parts than media of a predetermined shape and size, which is more controllable. Uniform preform shape media varies in size and abrasive composition to accommodate specific part shapes and provide different surface finishes.