The tool on a rigid basis is characterized by the type of abrasive material, its grainy, hardness, structure, bond, class of accuracy, shape and size. Each kind of tool on a rigid bundle is a body formed by abrasive grains, connected by various types of bonding. Abrasive grains can be freely positioned throughout the body, located only in the working layer, can be oriented so as to provide the most effective grinding process. The main forms of grinding wheels are shown in Figure 16.1.