Grinding wheels are made of natural or synthetic abrasive minerals that are combined in a matrix to form a wheel. While these tools may be familiar to those with home workshops, the general public may not be aware of these tools, as most are developed and used by the manufacturing industry. In this field, the grinding wheel has been around for more than 150 years.
For manufacturers, grinding wheels provide an effective way to shape and complete metals and other materials. Abrasives are often the only way to make parts with precise dimensions and high quality surface finish. Today, almost all manufacturing companies in the United States have grinding wheels for cutting steel bars and blocks; sharpening, drill bits and many other tools; or cleaning and preparing surfaces for painting or plating. More specifically, the accuracy of automotive camshafts and jet engines depends on the use of the grinding wheel. Without them, high-quality bearings cannot be produced. Without the fast working grinding wheel to shape and machine the parts, it is impossible to have new materials such as ceramics or composite materials.
Sandstone is an organic abrasive made of quartz particles held together by natural cement. It may be the earliest abrasive; it is used to smooth and sharpen vermiculite on the shaft. By the early nineteenth century, emery (a natural mineral containing iron and corundum) was used to cut and shape metals. However, before the discovery in the United States, Emeri’s quality instability and the importation of it from India prompted efforts to find more reliable abrasive minerals.
By the 1890s, the search produced silicon carbide, a synthetic mineral that was harder than corundum. In the end, manufacturers came up with the idea of producing better alternatives, synthetic corundum or alumina. In the manufacture of this bauxite derivative, they developed a more reliable abrasive than natural minerals and silicon carbide. Research on synthetic minerals has also led to the production of so-called super abrasives. The most important of this category is synthetic diamonds and minerals called cubic boron nitride (CBN), which is second only to synthetic diamond. Today, development continues, and seed gel alumina has just been introduced.
In the history of the entire grinding wheel, the bonding of the abrasive particles together has proven to be as important as the particles themselves. The success of the grinding wheel began in the early 1940s when rubber or clay-containing adhesive was introduced, and in the 1870s, a vitrified or glass-like adhesive was patented. Since then, the adhesives used in fast working grinding wheels have been constantly improving.
Grinding wheels are available in a variety of sizes, from less than 0.25 inches (0.63 cm) to a few feet in diameter. Our company produces 4.5-inch wheels, 9-inch wheels, etc. There are other sizes of wheels available. There are also a variety of shapes to choose from flat plates, cylinders, cups, cones and wheels. Although many techniques, such as bonding a layer of abrasive to the surface of a metal wheel for making a grinding wheel, this discussion is limited to wheels made of vitrified material contained in an adhesive matrix.