Cylindrical grinding (also called center-type grinding) is used to grind the cylindrical surfaces and shoulders of the workpiece. The workpiece is mounted on centers and rotated by a device known as a center driver. The abrasive wheel and the workpiece are rotated by separate motors and at different speeds. The table can be adjusted to produce tapers. The wheel head can be swiveled. The five types of cylindrical grinding are: outside diameter (OD) grinding, inside diameter (ID) grinding, plunge grinding, creep feed grinding, and centerless grinding.
Outside Diameter Grinding
OD grinding is grinding occurring on external surface a of an object between the centers. The centers are end units with a point that allow the object to be rotated. The grinding wheel is also being rotated in the same direction when it comes in contact with the object. This effectively means the two surfaces will be moving opposite directions when contact is made which allows for a smoother operation and less chance of a jam up.
Inside Diameter Grinding
ID grinding is grinding occurring on the inside of an object. The grinding wheel is always smaller than the width of the object. The object is held in place by a collet, which also rotates the object in place. Just as with OD grinding, the grinding wheel and the object rotated in opposite directions giving reversed direction contact of the two surfaces where the grinding occurs.
Tolerances for cylindrical grinding are held within ±0.0005 inches (13 μm) for diameter and ±0.0001 inches (2.5 μm) for roundness. Precision work can reach tolerances as high as ±0.00005 inches (1.3 μm) for diameter and ±0.00001 inches (0.25 μm) for roundness. Surface finishes can range from 2 microinches (51 nm) to 125 microinches (3.2 μm), with typical finishes ranging from 8 to 32 microinches (0.20 to 0.81 μm)