A grinding machine, often shortened to grinder, is any of various power tools or machine tools used for grinding. It is a type of material removal using an abrasive wheel as the cutting tool. Each grain of the abrasive on the wheel's surface cuts a small chip from the workpiece via shear deformation. Grinding as a type of machining is used to finish workpieces that must show high surface quality (e.g., low surface roughness) and high accuracy of shape and dimension.  In most applications, it tends to be a finishing operation and removes comparatively little metal, about 0.25 to 0.50  mm depth. However, there are some roughing applications in which grinding removes high volumes of metal quite rapidly. Thus, grinding is a diverse field.