For those new to CNC (computer numerical control) machining operations, the terms can be more confusing than in other types of manufacturing operations. It is important to keep in mind the general term of CNC machining can be used to designate many different services, and the provider will typically choose the method of producing parts which are the most cost-effective and efficient.
Two commonly used terms are CNC milling and turning operations. While they may be used interchangeably by some, they are actually two different processes with different methods and benefits.
A simple way to keep the terms CNC milling and turning separate is to consider the way the workpiece and tools move during the machining process. With CNC turning, the workpiece or the raw material to be formed rotates. With CNC milling the tool rotates around the workpiece.
The Basics of Turning
Turning is a highly effective way to shape cylindrical workpieces, but it can be used on other shapes as well. This is the operation of choice for facing, which allows for the surface of the workpiece to be perfectly shaped along the full length. It is also the ideal option for creating bored holes in the workpiece.
Depending on the material and the specifics of the CNC turning process, the speed of rotation and the type of turning tool used will be essential to creating the tight tolerances required.
The Basics of Milling
With the workpiece is held stationary in the CNC milling operation, the actual milling table moves as well as the cutting tool. This allows for very precise and complex shaping of the exterior surface of the workpiece.
With both CNC milling and turning operations, the process involves removing parts of the workpiece to create the desired shape. With the use of computer technology, this can be done to extremely tight tolerances both within the order and for all future orders.