Mill-Turn Machining: An Useful Solution for CNC Machined Parts

mill-turn process

In the past, CNC milling and CNC turning were two distinct processes carried out using two distinct machines – a milling machine and a turning machine, respectively. However, as technology advanced, both of these processes can be integrated into the same machine. Together, milling and turning processes are now known as mill-turn machining.

This article will serve as a guide in CNC mill-turn machining, considering the working principle of the mill-turn machine, common configurations, benefits, and possible fields of application.

What is CNC Mill-Turn Machining?

CNC mill-turn machining is a machining process that combines both CNC milling and CNC turning functionalities. To better understand this concept, let’s consider the differences between milling and turning.

CNC milling and turning

CNC milling is a machining process involving computerized controls and rotating cutting tools to progressively remove small pieces from the workpiece. This process is the most common CNC machining type. On the other hand, CNC turning is a machining process that involves holding bars of materials in place and rotating them while a tool associated with the machine removes materials to achieve the desired shape.

For a long, these two processes were performed independently. Now, the two processes can be integrated and done simultaneously by a highly precise and accurate CNC mill-turn machine. This can then lead to the creation of various shapes and geometries for different materials, including metals and plastics.

Working Principle of CNC Mill Turn Machines

CNC mill-turn machines can perform milling and turning at the same time. By implication, the CNC mill-turn centers do the work of both a mill and a lathe. Here’s an overview of the working principle of CNC mill-turn machines.

CNC mill-turn machining

First, a part is created. The CNC mill turn center starts work on the workpiece, which is a large block of material. The initial process, which is the turning process, is done using various cutting tools to remove material from the rotating workpiece. The aim of this stage is to shape the workpiece into cylindrical parts.

After the turning process, the workpiece moves past a rotational cutting tool, which also removes material from the workpiece. This is the milling stage, and the aim is to create flat and irregular surfaces.

Mill-turn machines produce CNC turning milling parts with a high degree of precision, accuracy, and speed. Also, the machine is flexible and is useful for several different shapes on a variety of materials.

Common Configurations of CNC Mill Turn Centers

Depending on the way the machine tool holds the workpiece, CNC mill-turn centers can belong to either of two configurations. They are:

horizontal CNC mill-turn machine

Horizontal CNC Mill-Turn Machine

This is the commonest configuration in many CNC turning centers, but its use in CNC mill-turn machines is not as pronounced. Here, the spindle of the CNC mill-turn machine has a horizontal orientation, and workpieces are therefore held horizontally. The cutting tools are out of the side of the holder.

This configuration is not as strong as the vertical configuration because gravity does not contribute to fixing the workpiece into the holding. Therefore, it is rarely used for large and heavy workpieces.

vertical CNC mill-turn machine

Vertical CNC Mill-Turn Machine

In vertical CNC mill-turn machines, the spindle of the machine has a horizontal orientation, and workpieces are held vertically. The cutting tools in this configuration are in a similar direction as the holder. Because of gravity, vertical CNC mill-turn centers are stronger and more stable than their horizontal counterparts.

This configuration is particularly useful when machining large and heavy workpieces, as gravity contributes to the solid seating of these large materials into the holding.

Benefits of CNC Mill-Turn Machining

CNC turning and milling parts are becoming increasingly common in many industries today. This is large because of its benefits over traditional individual milling and turning machines. Below, we consider some of these benefits.

Machining Complex Parts

There is a limit to the geometric complexity that traditional machining tools can handle. Also, when machining some complex parts, machinists may need to transfer parts from one machine to another machine.

The CNC mill-turn machine solves this problem as it can create complex geometric shapes, and without the need to transfer materials as well. This improves both the quality of the product and the efficiency at which manufacturing companies can create these complex products.

cnc turning operation

Improve Speed

One of the major selling points of CNC mill turn machines is the speed at which they carry out their operations compared to traditional machining tools. Traditionally, machinists would need to set up a workpiece on a lathe and complete turning operations on a part, before setting up the workpiece on a mill and commencing milling operations.

But since the CNC mill turn machine can carry out both processes simultaneously, machinists only set up the workpiece once and don’t have to move the parts until the process is completed. This hastens production and increases productivity in manufacturing industries.

Better Accuracy

CNC machines generally are very accurate, and this holds true for CNC milling and CNC turning operations. However, there is even increased accuracy with CNC mill-turn centers. This is largely because there is no need for the machinist to set up the raw material (workpiece) more than once over the course of the entire operation. This is in contrast to handling milling and turning operations on separate machines where operators still need to adjust and move parts after one of the operations is complete.

The high accuracy and reproducibility that CNC mill-turn machines offer are of even greater benefit when manufacturing parts where tolerance values are marginal. With such parts, even the slightest of errors when moving and readjusting parts can lead to the failure of the entire CNC machining process.

Other Machining Activities

Aside from milling and turning, CNC mill-turn machines can be programmed to perform several different tasks. This, in turn, means manufacturing industries can use the machines for a variety of machining projects.

Also, some of the tasks that machinists would otherwise concern themselves with, like loading workpieces, removing parts, and probing can be fully automated and handled by the machine. The result is more time for the operator to handle other tasks, and generally, an increase in productivity in the industry.

Applications of CNC Mill-Turn Technology

Considering the fact that operators can program CNC mill-turn centers to carry out a wide variety of complex operations, it is no surprise that they are employed for a lot of tasks in a lot of industries. Some of these industries include:

CNC mill-turn technology

Aerospace: CNC mill-turn machines can help in the manufacturing of airplane and satellite components.

Medical: The medical industry is not new to CNC machining, and manufacturers often turn to CNC mill-turn centers for implants and prostheses, and other medical equipment with similarly complex designs.

Automotive: Steering equipment, engine components, and shafts are typical parts that manufacturers use CNC mill-turn centers to create.

Electronics: Complex electronic hardware parts, like motherboards, circuit boards, and amplifier housings, usually require a high degree of precision and accuracy to manufacture. As CNC turning milling parts usually guarantee this level of precision and accuracy, mill-turn operations are common in the electronics industry.

Energy: The oil and gas industry utilizes CNC mill-turn machining for parts that ensure the proper flow of fuel. Also, nuclear power plants often require complex parts with low tolerance limits, and CNC mill-turn machines can help accomplish this.

Get Quality CNC Mill-Turn Machining Services at WayKen

CNC mill-turn machining is getting more popular by the day in manufacturing industries. This is not surprising, considering the benefits it offers over traditional tools. However, the benefits of these mill-turn machining services are only maximized when done correctly and by the right professionals.

Fortunately, at WayKen, we have the right professionals to help you get high-quality mill-turn machined parts. We offer a full range of mill-turn services at affordable prices and fast turnaround. Just upload your CAD files and get DfM feedback today!


From CNC turning and CNC milling basics, it is clear that both operations are primarily different in that milling involves rotation of the tool, with the workpiece, held still while turning involves rotation of the workpiece. Traditionally, machinists had to complete one operation first before moving on to the next.

However, with the advancement of technology, it is possible to carry out both operations simultaneously using a CNC mill-turn machine. Aside from the relatively fast speed of production, CNC mill-turn centers also guarantee high accuracy and precision for complex parts. This has, therefore, justified its use in many industries today.

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