What is the Difference Between CNC Milling and CNC Turning

Custom machining services provide valuable resources for business and industry, such as defense, optics, pharmaceuticals, machinery, and automobiles. Some parts are manufactured by cnc machines, and some are manufactured by cnc lathes. Many people who work in manufacturing are not quite aware of the difference between CNC milling and CNC turning.

From the outside, the two processes seem very similar (ie removal of metal). However, in many ways, they are very different in the way they complete the required parts. In general, turning and milling are often referred to as “CNC machining”-our customers often request CNC machining instead of turning or milling as the name suggests. Of course, it is SANS’s job to ensure that the most appropriate process is used every time. Today we will introduce the difference between turning and milling and the pro and cons about CNC machining.

What is CNC Turning?

CNC turning takes place on a machine tool called a lathe. The processing principle is that the workpiece is rotating and the tool is fixed. On this machine, the material can rotate, but the tool remains stationary. Usually, a chuck is used to fix the part on the rotating spindle. The chuck can be clamped with jaws or hydraulic devices to fix the part in place.

When the spindle rotates, the turret equipped with cutting tools moves toward the raw material and removes it as the material rotates to form the desired shape. The tools in the turret are very strong, and the turret rotates to change the tools that engage with the material. Since the part is rotating while the tool removes material, the final shape is some form of rotating profile.

The turned parts range from simple rings to complex curved parts: spheres, cones, cylinders, and other shapes, such as square or hexagon.

What is CNC Milling?

Similar to CNC turning, CNC milling is also an automated manufacturing process. Completed by computer numerical control equipment. Use a milling cutter to remove the material surface by advancing in a certain angle direction. The object of the CNC milling machine is fixed at a certain position of the machine tool, and the milling cutter is rotated at a high speed under the clamp of the fixture.

When touching the workpiece, it can process planes and grooves on its surface. It can also process various curved surfaces, gears and other CNC milling machines.

The machine for milling the workpiece on the CNC milling machine can process planes (horizontal planes, vertical planes), grooves (keyways, T-slots, dovetail grooves, etc.), and gear parts (gears, spline shafts, sprockets, etc.) , Spiral appearance (threads, spiral grooves) and various curved surfaces.

In addition, it can also be used to process the reversal external surface, inner hole and block operations. Because of the multi-tool intermittent cutting, the productivity of the CNC milling machine is higher , The machining principle of CNC milling machine is that the workpiece is fixed and the tool is rotating. These machines can also be horizontal or vertical, depending on the tolerance and weight of the workpiece.

CNC milling machines can be controlled in one of two ways: by computer or by manual operation. Computer programming allows the machine tool to perform the precise cutting required, while manual override allows the CNC machine tool operator to slow down or speed up or adjust the process as needed.

What are the Differences Between CNC Milling and CNC Turning?

1) The movement path of the tool and the workpiece

CNC turning: The workpiece rotates and the turning tool moves along a straight line or a curve.

CNC milling: The milling cutter rotates and the workpiece moves along a straight line or a curve.

2) Machinery

CNC turning: Using CNC lathes or lathes, it can also be used for processing including drilling, reaming, tapping and knurling.

CNC milling: Using CNC milling machine or milling machine, it can process plane (horizontal, vertical), groove (keyway, T-slot, dovetail groove), gear, spiral surface (thread, spiral groove) and various curved surfaces.

3) Ability or purpose

CNC turning: Mainly used for machining inner and outer cylindrical or conical surfaces, such as shafts, bushes, sleeves, etc.

CNC milling: used to machine flat and irregular surfaces, such as grooves, grooves, gears, threads and special molding surfaces of molds, which can create complex shapes and features

4) Advantages

CNC turning: better outer surface during machining

CNC milling: better results when machining large surfaces

5) Tool function

CNC turning: the tool is a single point

CNC milling: multi-point tool

6) Cutting

CNC turning: continuous cutting, keeping the cutting tool in contact with the workpiece

CNC milling: Intermittent cutting, cutting tool tooth engagement and disengagement

7) Chip

CNC turning: chipping, discontinuous or continuous chips

CNC milling: always produce discontinuous chips

Advantages and Disadvantages of CNC Machining

turning partsAdvantages

1 CNC machining can be multi-coordinate linkage, can process parts with complex shapes, and even process some unobservable parts.

2 The CNC lathe itself has high machining accuracy, strong rigidity, can choose a favorable machining dose, and high productivity (generally 3 to 5 times that of ordinary machine tools);

3 CNC lathe processing machine has a high degree of automation, which can reduce labor intensity;

4 The quality of products processed by CNC lathes is easy to control

5 The number of tooling is greatly reduced, and complex tooling is not required for machining parts with complex shapes. If you want to change the shape and size of the part, you only need to modify the part processing program, which is suitable for new product development and modification, and can save production preparation time.

6 The processing quality is stable, the processing accuracy is high, and the repeat accuracy is high, which is suitable for the processing requirements of aircraft.

7 The production efficiency is higher in the case of multi-variety and small batch production, which can reduce the time of production preparation, machine tool adjustment and process inspection, and reduce the cutting time due to the use of cutting volume.


1. The cost of machine tool equipment is expensive, which is not conducive to processing large quantities of parts,

2. High requirements for maintenance personnel and high personnel costs

3 The system is complicated, the maintenance cost is high, and a good working environment is required

The above are the difference between CNC turning and milling process, the advantages and disadvantages of CNC machining. If you have related questions or related projects, please inquire. Our professional team will give you a satisfactory result.

Inquiry Now !

Leave a Reply

Your email address will not be published. Required fields are marked *