Rough translucent glass with emery or chemical treatment.It is the common name of ground glass.Ground glass like shadow is blurred dense shadow, such as: lobar pneumonia, SARS and other diseases of X-ray.Grinding wheel is by the binder will be ordinary abrasive condensation into a certain shape (mostly round, the middle hole), and has a certain strength of the condensation abrasive.It is usually composed of abrasives, binders and pores, which are often referred to as the three elements of the condensing abrasives.According to the different classification of binders, rare grinding wheels are ceramic (binders), resin (binders) and rubber (binders).Grinding wheel is one of the most widely used abrasive tools, which can stop coarse grinding, semi-fine grinding, fine grinding, grooving and blocking on the outer circle, inner circle, three-dimensional and various types of surface of metal or nonmetal workpiece.