Grinding wheel is the main tool for grinding. It is a porous object composed of abrasive and bonding agent. Abrasives, binders and pores are the three basic components of a grinding wheel. Grinding wheels are expendable wheels composing of an abrasive compound. A grinding wheel having multiple cutting edges made up of many hard a particle called as abrasives. The abrasives are crushed to have sharp edges for cutting operations. http://www.winoneabrasives.com/grinding-wheel/