CNC Turning vs. CNC Milling: Which is Better for Parts Production?

A fundamental aspect of manufacturing is parts production. Companies and individuals that produce aftermarket and customized parts need to use the best machining processes to deliver high-quality products. One question that constantly arises in the engineering and manufacturing industry is which machining method is best suited for parts production: CNC turning or CNC milling?

This article seeks to compare the two machining processes and provide insights into selecting the best option for parts production.

CNC Turning: What is it?

CNC turning is a precision machining process that involves a rotating workpiece, a stationary cutting tool, and a lathe. During the machining process, the cutting tool removes material from the workpiece in a circular motion to create the required shape. The workpiece is held in place by a chuck, and the rotational movement is usually driven by a spindle.

CNC Milling: What is it?

CNC Milling, on the other hand, is a process that uses a milling machine or a mill to grind or cut away material, producing the desired shape. The milling machine consists of a spindle, a cutting tool, and a worktable. During the machining process, the workpiece is mounted on the worktable and moves in different directions to enable milling in various directions. The cutting tool, also called the end mill, rotates, and as it moves across the workpiece, it removes material.

CNC Turning vs. CNC Milling: What are the Major Differences?

1. Cost

CNC turning and milling processes come at different costs. Turning is a less expensive process as it requires fewer tools, unlike milling, which requires several cutting tools. However, when using a lathe, the workpiece is often fastened in place, which limits the design possibilities.

2. Material

CNC turning can work with round or cylindrical shapes, while CNC milling can work with more complex shapes. Turning works mainly on cylindrical parts and bars, while milling can work on a wide range of materials, such as metals, plastics, and wood.

3. Speed

CNC milling can be completed at higher speeds than turning, thanks to the multi-axis functionality of the milling machines. Turned parts usually require multiple passes, while a CNC milling machine can perform the required cuts in a single pass.

4. Accuracy

In terms of precision, CNC mills offer greater precision than turning. Milling machines use a higher number of cutting edges than turning tools, giving them improved accuracy.

5. Setup Time

Setting up a CNC turning machine requires less time compared to a CNC milling machine. CNC turning only requires the workpiece to be held in a lathe, and the tool is adjusted. On the other hand, CNC milling requires multiple tools, which require changing, making the setup process longer.

When to Use CNC Turning

CNC turning is suited for parts that require the manufacture of rotational (cylindrical) shape, such as bolts and screws. It also works well with more challenging materials such as plastics and specialty alloys. CNC turning is ideal for high-precision work, where tight tolerances are required.

When to Use CNC Milling

CNC milling is an excellent option for producing parts with complex geometries, shapes, and angles. It is also perfect for manufacturing parts in low volumes, and where customization is required. Additionally, milling can be used for high-volume production, as it is faster than turning.

Conclusion

In conclusion, choosing between CNC turning and CNC milling depends on the requirements of the production process. CNC turning is suitable for simple designs and cylindrical shapes, while CNC milling is suitable for complex shapes and low-volume production of custom parts. When designing a part, it is crucial to consider the advantages of both methods and decide which will provide the best results. Ultimately, the two processes can complement each other in creating high-quality parts for various applications.