Machining

Machining is a collection of material-working processes in which power-driven machine tools, such as lathes, milling machines, and drill presses are used with a sharp cutting tool to mechanically cut the material to achieve the desired geometry.
The three principal machining processes are classified as turning, drilling and milling.
Turning operations are operations that rotate the workpiece as the primary method of moving metal against the cutting tool.
Milling operations are operations in which the cutting tool rotates to bring cutting edges to bear against the workpiece.
Drilling operations are operations in which holes are produced or refined by bringing a rotating cutter with cutting edges at the lower extremity into contact with the workpiece.