Grinding is the process of highly precise removal of material using abrasive grains that are made out of things such as: silicon carbide, aluminum oxide, cubic boron nitride, and diamond grit, etc. Grinding is a very precision oriented process and the rate of material removal is low when compared to other processes such as milling and drilling.
The abrasive grains are either bonded with additives in a furnace (bonded products), loosely embedded on a fiber backed paper (coated products), or mixed in a paste. Bonded products are:grinding wheels, honing sticks, segmented blocks, etc. Bonded products are used on grinding machines. Coated products are different forms of emery papers and sand papers. The process of grinding has been around for centuries as stones were grinded many years ago to make spear heads and arrow heads, etc.
Grinding is generally performed when an item needs to be smoothed or shaped into a different form. Just about any type of hard substance can be grinded such as steel, ceramics, glass, and diamonds. The process is used on auto engines, to sharpen knives, and to make things such as drills, ball bearings and glass lenses.
There are various types of grinding such as conventional grinding, internal grinding, form grinding, centerless grinding, peel and HEDG grinding, cam grinding, contour grinding, crank grinding, cylindrical grinding, surface grinding, including pendulum grinding, creep-feed grinding, vertical and horizontal grinding, reciprocating and rotary grinding, top and bottom grinding and jig grinding.
The major methods of grinding are surface grinding, internal grinding and form grinding. Cylindrical grinding can be used to grind cylindrical objects that are rotated between rotating centers. Surface grinding involves mounting the component on a reciprocating magnetic machine bed and feeding the rotating grinding wheel from the top or the side. Contour grinding involves giving a form to the grinding wheel and feeding the wheel to the component. Internal grinding involves removing the metal from the internal diameter or internal form. The grinding zone needs to be flushed with clean coolant to remove the heat and the burr. Diamond dressers (single/multi point) are used to remove the blunted grains from the wheels and expose the fresh grains.