A grinding wheel is a precision tool with a multitude of cutting tips. It consists of abrasive grain held in a matrix of bonds and of corresponding ones pores. The abrasive grains form the cutting tips that are held in place by the bond. The Pores enable the coolant supply and form space around the chips from the grinding gap remove. Vitrified bonded grinding wheel have a porous structure in which the grains are held together by glass or ceramic bond bars.