Metal media and abrasives include metal shot or balls, cut wire, crushed metal grit, and shaped media for applications such as blasting, ball burnishing, peening, mass finishing (vibratory or tumbling), and deburring. Products are also used in bonded wheels and coated abrasives. Metal abrasives, metal grit, metal shot, and metal media feature a combination of hardness and toughness that is achieved through composition and heat treatment. Metal abrasives are made with metal-forming techniques that produce shape configurations which are unattainable or difficult to attain efficiently in ceramic or plastic media types. In some mass-finishing applications, metal media can be used for years because the metal finishes the parts through a burnishing or rubbing action.
Metal media and abrasives are usually made from aluminum, cast iron, steel, stainless steel, or zinc. They differ in terms of type and shape. Choices for type include metal grits or metal abrasives, and meal media or metal shapes. Choices for shape include balls or beads, ball cones or satellites, regular cones, crushed or irregular particles, cylinders, diamonds, ovals or ellipses, tapers or pins, cut wire shot, and cast shot. Cut wire shot consists of round, cut wire or irregular shapes. Cast shot is rounded and available in a variety of sizes. The atomization or droplet formation process may produce a range of diameters. Unless conditioned, however, metal shot may not be perfectly round.
Product specifications for metal media and abrasives include bulk density, media size, and grit grade or shot size. Bulk density is the mass per unit area, accounting for internal porosity. Tap density and lose pack density are often used to understand particle shape and interparticle parameters such as friction and flowability. There are two media sizes: media dimension A and media dimension B. There are also several grit grades and shot sizes. Choices for metal abrasives include JIS, mesh graded, micron graded, SAE, and specialty. JIS is an acronym for Japanese Industrial Standards, while SAE is an acronym for the Society of Automotive Engineers.
There are many different applications for metal media and abrasives. Some products are used in blasting, blending and intermediate cutting, burnishing, cleaning or surface preparation, deburring or deflashing, and descaling or stripping applications. Others are used for fast cutting or aggressive cutting, grinding or ball milling, peening, or polishing. Metal abrasives for tumbling and mass finishing applications are also available.