A grinding wheel is a resin bonded abrasive composed of abrasive grains which are held tightly together by a bonding agent and reinforced with a woven material. The main function of a grinding wheel is to remove material from a workpiece in an abrasive action with each grain acting as a cutting tool.

Abrasive grains are particles of man-made abrasive compounds. Most manufacturers use recycled grains, United Abrasives uses high quality virgin grains that are made to exacting specifications. The chemical structure of the grains determines the shape, sharpness, hardness and friability of the abrasive. Typical grains are:

Aluminum Oxide

  • A tough grain used for cutting metals and without excessive fracturing

Silicon Carbide

  • A hard and sharp abrasive used on concrete


  • A fine, dense crystalline grain that is used for rugged stock removal

Ceramic Aluminum Oxide

  • Two times tougher than standard aluminum oxide

The resinoid bonding agent that holds the grains together determines the
resistance of the wheel.

United Abrasives uses multiple layers of long stranded fiberglass as the woven material to form a strong reinforcement layer that allows the wheel to be used at maximum RPM and withstand lateral pressure applied during use.

These three components are measured and combined and then pressed using an automated process during manufacture to form a grinding wheel.

United Abrasives’ labels are incorporated into the process and remain intact throughout the life of the wheel. For a quick overview on labeling, check out our post on How to Read a Grinding Wheel Label.