CNC Machines are multi-faceted devices, availing machinists an endless array of possibilities to create, refine and finish products from a diverse range of materials. Because of the use of Computerized numerical controls, these machines can manufacture products to a high degree of accuracy using many methods.

Some of the most popular manufacturing techniques include turning and milling – At first glance, these two processes, which both involve the systematic removal of material from a workpiece, look similar. What then is the difference between these 2 machining methods? The short answer is this –  CNC milling involves a rotating tool while CNC turning essentially rotates the part around the tool for cutting.

Today, we cover these two techniques in detail and highlight the major differences between them. Read on below to learn more about CNC milling and CNC turning.

CNC Milling

CNC milling is a machining process that involves the use of a cutting tool to remove material from a workpiece. In CNC milling, the workpiece remains stationery while the cutting tool does the movements and rotates around the material till the final part is formed. The movement in a particular angle and direction is dictated by the computer numerical programming, allowing for high precision when delivering the cuts. 

CNC Turning

CNC turning, on the other hand, is commonly used in creating cylindrical parts like shafts and tubular shapes like brass shoulder bolt. When turning, material/workpiece is fed into a high speed rotating lathe, while a single-point cutter shaves off portion of the material till the desired part is formed.

CNC turning is suitable for non-ferrous metal part finishing, and the machining mechanism is such that the cuts are delivered smoothly, allowing large amount of the material to be cut at high speed. During turning, only the workpiece moves while the cutting tool remains stationery

CNC Milling vs CNC Turning

·    Cutting tool and Workpiece motion

The basic difference here is that the workpiece remains stationery in CNC milling while the cutting tool rotates to remove material from the workpiece.In CNC turning, the workpiece is rotated while the cutting tool remains stationery.

·    Capabilities

CNC turning is majorly employed for machining inner or outer conical or cylindrical parts like sleeves, shafts and bushes while CNC machining is ideal for machining flat and jagged surfaces. It is used for making slots, threading, grooves and gears.

·    Machines

CNC turning employs lathes or turning machines. CNC milling uses mills or milling machines. CNC mills are able to process horizontal, vertical, spiral and curved surfaces while CNC lathes can perform drilling, tapping, knurling and tapping CNC operations.

·    Tool considerations

CNC milling uses a multi-point tool cutting system while CNC turning uses a sing-point cutting tool.

·    Chip production

Turning produces discontinuous, fragmented or continuous chips while milling always results in discontinuous chips

·    Cutting

CNC lathes can perform turning operations through continuous cutting where the cutter tool remains in contact with the workpiece till the final cut is made. CNC milling uses intermitted cutting where the cutter tool may contact and disengage the workpiece from time to time.

What is best for you?

While there is never any one-size-fits-all approach, the following may be considered as simple rules of thumb:

·    Cost

When the cost per part, turning may be a more effective price option. However, whenever accuracy and precision for complex geometries are involved, CNC milling is always the go-to solution.

·    Quantity

CNC turning is more suited for larger parts and higher volumes. CNC milling on the other hand is ideal for small parts and low-volume manufacturing.

·    Geometry 

Generally, if it’s round, you’ll most likely need to turn it. If it’s not round, round and complex, CNC milling will be more effective.

FirstPart CNC Machining in China

FirstPart is one of China’s leading manufacturing hub for Additive, CNC and Conventional manufacturing techniques. We boast of excellent in-house capacity, labour force and logistics while delivering exceptional value for money.

Our array of services include CNC machining, CNC turning, CNC milling, 3D printing, Rapid Tooling, Die casting, Rapid prototyping, Plastic Injection Molding, Urethane

Casting, Aluminium Extrusion, Post-machining/Finishing services and much more.

As we understand the global challenges that is faced by new businesses in these times of the Coronavirus, we offer product tooling, mass production, bridge tooling and low-volume prototyping/manufacturing with very flexible minimum order quantities (1 to 100,000). Our services are online, scalable and innovative, with a team of engineers and design experts available to support you through your entire product development cycle.