Aluminum Oxide – Aluminum Oxide is brown or reddish in color and a man-made abrasive. It is durable with tough cutting edges. It offers long life and is highly wear resistant even under stress applications. Its applications include aluminum, ferrous metals (including alloy steel), hardwood, and leather.
Crocus – Crocus is reddish brown in color. It is a soft material made from iron oxide. It is the finest natural grain produced. Its applications include cleaning and extremely fine polishing of soft materials such as gold.
Emery – Emery is a dark gray round-shaped natural grain. It is better used as a polishing grain than a cutting grain. It is used for cleaning and polishing metals.
Flint – Flint is a low cost white crystalline nonconductive mineral. It is only available with a paper backing. Its is used for low-pressure hand applications, paint removal, and sanding in the electrical motor industry.
Garnet – Garnet is a reddish brown natural grain. It is relatively sharp and has a medium hardness. Its durability cannot be compared to that of synthetic abrasives. It is used for finishing applications in soft woods such as fir or pine.
Silicon Carbide – Silicon Carbide is black in color. It is a sharp, hard synthetic abrasive. Its friable grains fracture to continually expose new cutting edges and permit fast stock removal. Its applications include aluminum, bronze, non-ferrous metals, and non-metallics such as glass, plastic, rubber and soft woods.
White Aluminum Oxide – White Aluminum Oxide is a friable man-made abrasive. Its sharp, cool cutting edges easily break down under pressure to expose new cutting edges. Its applications include non-ferrous metal finishing and production wood sanding.
Zirconia Alumina – Zirconia Alumina is a bluish gray colored ultra rugged synthetic abrasive. It has large fracture planes and is a sharper, more blocky grain than aluminum oxide. It self-sharpens as it cuts and is available only in coarser grits. It is used for heavy duty grinding on all ferrous and non-ferrous metals, and rough planing of wood products.
What is the structure?
Structure is basically the spacing between abrasive grains. An open structure would be 12 or higher while a closer structure would be 6 or so. Here again, the structure depends on a variety of factors not the least