Abrasive blasting is the general term applied to finishing processes that entail the high-pressure propulsion of a stream of abrasive material onto the surface of a workpiece. Abrasive blasting can serve many surface finishing purposes, such as removing contaminants or previous coatings, altering the shape and smoothing or roughening the surface.
There are many types of abrasive blasting applications, each of which requires the use of different types of blasting materials, referred to as blasting “media.” Finishing Systems has assembled this abrasive blasting media guide to help you select the most appropriate material for your specific finishing processes.
One note: the terms “sandblasting” and “abrasive blasting” are often used interchangeably. A conventional “dry” sandblasting process that uses traditional sand is not recommended for most applications. Blasting with sand generally requires twice the amount of material, making it cost-prohibitive for many companies.
Glass Beads: Glass is not as aggressive a blasting media as other materials, such as steel shot or silicon carbide. However, it is an excellent choice for applications that require a softer, brighter finish. It is well suited for stainless steel applications. Glass beads can also be recycled multiple times.
Aluminum Oxide: Aluminum oxide is characterized by its superior hardness and strength. It can be found in applications ranging from anti-slip surfaces, industrial applications as a blasting media, and as a raw material in refractories. It is designed for abrasive pressure blasting of almost any type of substrate: glass, granite, marble, and steel. Due to its ability to deeply etch it is used in the preparation of surfaces prior to painting or coatings.
Plastics: Plastic abrasive is a dry thermoset cleaning media made from crushed urea, polyester or acrylic. Each varying and available in a range of hardness and particle size. Plastic is generally regarded as the best media for mold cleaning, blasting of plastic parts, or in applications where the removal of the substrate material is not permitted. Common industries include automotive, aviation, boating, electronics and industrial applications.
Silicon Carbide: Silicon carbide is the hardest abrasive blasting material available, making it the best choice for your most challenging surface finishing applications. It is available in various colors and purities. Its primary use ranges from bonded abrasive tools, lapping, polishing, glass etching and general purpose heavy duty blast cutting applications.
Steel Shot & Grit: Steel abrasive is a cost-effective alternative to other abrasives due to its toughness and high recyclability. It can be used on a variety of surfaces to effectively remove contaminants, texture a surface for proper adherence of a final coating, or in peening (hardening) applications. The correct size, hardness and shape play a significant role in the proper media selection.
Starblast: Starblast™ is a mined loose blend of coarse and fine staurolite sands with extremely low levels of silica making it an ideal general purpose blasting abrasive. It is perfect for removing scale and corrosion from steel surfaces, while offering a low dust level for improved visibility.
Walnut Shells: Walnut shell abrasive is a hard naturally occurring material made from crushed walnut shells. It is the harder of the soft abrasives, available in a variety of sizes for blast cleaning and polishing softer surfaces that could incur damage from harsher abrasives. Typical applications include polishing of soft metals, fiberglass, wood, plastic and stone. It can also be used in tumbling operations for polishing gems and jewelry.
Corn Cobs: Corn cob abrasive is a granular abrasive manufactured from crushing the dense woody ring of a corn cob into various grit sizes. It is the softer of the naturally occurring abrasives making it ideal for cleaning, deburring, burnishing and de-flashing applications. Common industries include jewelry, cutlery, engine parts, fiberglass and the removal of graffiti or debris from wood, brick or stone.
