CNC milling and CNC turning use a controlled process to remove unwanted material from a workpiece. In CNC milling, a workpiece is placed on a tabletop and rotated against stationary cutters to shape the object into the final form. In CNC turning, the workpiece is placed on a lathe and rotated or turned at a fast rate against cutters that move to form the final piece. CNC milling and CNC turning both use a computer in conjunction with the cutters to produce objects milled with higher accuracy, precision, and speed.
CNC milling and CNC turning are best used as secondary finishing processes. Which process to use depends on what the workpiece is and what type of cuts are needed. CNC Milling operations are best used for flat or sculptured surfaces on square or rectangular blocks. CNC Turning operations are best used for cylindrical or conical workpieces. The workpiece is held by a lathe and spun at high RPMs while the moving cutters shave away the unwanted materials.