Abrasives

Abrasive materials are hard crystals that are either set in nature or manufactured. The greatest in quantity commonly used of such materials are aluminum oxide, silicon carbide, cubic boron nitride, and diamond

Other materials of the like kind as garnet, zirconia, glass and even walnut shells are used for special applications.

Abrasives are primarily used in metalworking because their grains can penetrate plane the hardest metals and alloys. However, their great hardness also makes them suitable for working with similar other hard materials as stones, glass, and certain marks of plastics . Abrasives are also used with relatively yielding materials, including wood and rubber, because their use permits high stock removal, long-lasting cutting ability, beneficial form control, and fine finishing.

Applications for abrasives generally fall in the following categories: 1) cleaning of surfaces and the coarse removal of exces material, similar as rough off-hand grinding in foundries; 2) shaping, as in form grinding and tool