How does a cylindrical grinding machine produce a round surface?

A cylindrical grinding machine produces a round surface by rotating the workpiece as it is fed against a rotating [grinding wheel]. This process relies on the precise interaction between the workpiece's rotation and the abrasive action of the wheel to achieve high levels of accuracy, often within tolerances of 0.0001 inch (0.0025 millimetre).12

The specific geometry of the finished part is determined by how the workpiece is moved relative to the wheel and the profile of the wheel itself, which can be shaped using a diamond or other dresser. While a cylindrical grinder rotates the workpiece to create an external round form, internal cylindrical grinding involves moving a smaller wheel back and forth inside a hollow workpiece that is held in a rotating chuck.1