A Grinding Wheel is a cutting tool in which millions of microscopic abrasive grains are bond together. Here, each abrasive grain acts like a spiky tool. As shown in the image, the abrasive grains are held together in the porous structure of the grinding wheel by a bonding substance (bond). The wheels are expendable wheels composing of an abrasive compound. It is a precision tool with thousands of cutting points on its surface - abrasive grains that are held in place by a bond matrix (hence these are known as bonded abrasives) and separated by pores. Grinding Wheel is very efficient.