What is CNC Turning?

CNC Turning Definition

CNC Turning

CNC turning, a short for Computer Numerical Control Turning, is a modern automatic CNC machining process to creat cylindrical components by removing material from a workpiece. It uses a computer control system to precisely control the movement of cutting tool, and shape out the desired dimensions in a high effecient way. For the advantage of flexibility, CNC turning can meet the machining requirement of different parts, so it has a wide range of application in today’s manufacturing.

CFS Machine Shop has the in house CNC turning capability to produce custom parts with high precision and high effciency. Due to the repeatability and automation, our cnc turning services support a variety of materials and large production volumes.

The main features of NC turning include high precision, high efficiency, repeatability and automation. It can be used to process a variety of materials, such as metals, plastics and ceramics, and is suitable for multiple areas of the manufacturing industry, such as aerospace, automotive, medical devices, etc. CNC turning also has the flexibility to easily adapt to the processing needs of different workpieces, just modify the program, so it has a wide range of application prospects in production.

How Does CNC Turning Work?

1. Confirm the Geometry and Size of The Workpiece

Before turning, it is necessary to confirm the geometry and size of the workpiece according to the CAD drawings. This includes the diameter, length, surface finish, machining accuracy and other parameters of the workpiece.

2. Choose The Right Turning Tool

Choose The Right Turning Tool

In CNC turning process, manufacturers should select a tool suitable for the workpiece material and geometry, such as cutting edges, angles, hardness, etc. At the same time, they also need to determine the process parameters, such as rotate speed, feed speed, cutting depth, etc.

3. Adjust The Movement Shaft of The Lathe

Before turning, it is necessary to adjust the various movement axes of the lathe, such as the longitudinal feed shaft, the transverse feed shaft, the main shaft, etc. This will help to ensure that the turning tool can cut the workpiece in the correct position and direction.

4. Parameter Setting of Cutting Process

Parameter Setting of Cutting Process

According to the material of the workpiece and the required machining requirements, we always set the lathe speed, feed speed, cutting depth and other parameters in advance, so that the expected machining effect can be achieved.

5. Turning Process

In the turning process, it is necessary to move the turning tool along the axial and transverse axis of the workpiece to cut or grind the workpiece, while ensuring that the contact gap between the turning tool and the workpiece surface during the cutting process is as small as possible.

6. Inspection

After the completion of the turning process, CFS Machine Shop always checks the workpiece to confirm whether the parameters such as the size, shape and surface finish meet the requirements, and whether there are defects, deformation and other problems.

Specific Example:

Taking the CNC turning of a shaft part as an example, we need to analyze its structural characteristics, size requirements and machining difficulties. Because of the high surface roughness requirements of this part, we need to use high-speed steel tools for high-speed cutting. In actual operation, we first clamp the workpiece on the CNC lathe, and then set the appropriate cutting speed, feed rate and cutting depth. Next, the CNC system is started to make the turning tool rotate according to the preset trajectory. During the machining process, we also need to constantly adjust the cutting parameters to maintain the balance of cutting quality and efficiency. Finally, through the analysis of the machining results, we can find out whether the dimensional accuracy and surface roughness of the part meet the design requirements.

Types of CNC Turning Operations

Straight Line Turning

Linear turning involves the use of cutting tools to reduce the diameter of the workpiece evenly. The technology is designed to machine the material to a specified thickness. It can quickly remove part of the material, thereby preventing changes in the diameter of the product. It is sometimes referred to as a rough machining, and requires further machining to obtain dimensional accuracy.


This operation involves the machining of jagged, angled or crossed cutting patterns on the surface of the workpiece. The process usually causes a firm grip, as the pattern increases friction. It is also suitable for making bolts and nuts for threaded holes. It is worth noting that this operation may require a specially designed knurling tool.


Segmentation is a processing technique that uses a single point cutting tool to create a deep groove in the material, removing its internal sections. As the name suggests, it results in producing parts or cutting off parts of the original.

Taper Turning

Taper turning involves gradually reducing the diameter of the material from one end to the other. The angular movement between the material and the cutting tool results in a transition and reduction in the diameter of the workpiece. As with most turning operations, the final product is cylindrical.


Threading is another CNC turning process, in which the cutting tool moves along the side of the material to cut the threads onto the external parts of the workpiece. A thread is a spiral groove with a specific length and spacing.


This turning operation creates a narrow cut – a groove – in the workpiece. It involves the action of a sharp tool head on the material to cut out the same width as the cutting tool. With the help of a variety of cutting tools, wider grooves can be machined.

Common CNC Turning Materials


Metal materials are one of the most common CNC turning materials, including steel, aluminum, copper, titanium, nickel and so on. These metal materials usually have the characteristics of high strength, hardness and good electrical conductivity. They are often used in aerospace, automobile manufacturing, machinery manufacturing and other fields. When turning metal materials, it is necessary to select different cutting tools and machining parameters according to the hardness and strength of the material.


Plastic is another common CNC turning material, which is widely used in daily necessities, electronic products, communication equipment and other fields. Plastic materials usually have excellent wear resistance, corrosion resistance, low density and other characteristics. Different types of plastics also have different strength and rigidity. When machining plastic materials with CNC turning machines, it is necessary to pay attention to cutting speed, feed rate and the use of coolant.

Composite materials

Composite materials for CNC turning usually include carbon fiber, glass fiber and so on. With light weight, high strength, high rigidity and other characteristics, they are widely used in aerospace, shipbuilding, sports equipment and other fields. When machining composite materials, special attention needs to be paid to the selection of processing tools and the control of processing parameters, which can avoid cracks and damage of these materials.

Advantages of CNC Turning

High Precision

CNC turning has the advanatage of high precision. The traditional mechanical turning needs to rely on the operator to control the movement of the tool manually, which is easy to be affected by human factors and difficult to achieve high-precision machining. CNC turning controls the movement of tools through the computer, which can achieve accurate machining and ensure the accuracy of the sizes of the part.

High Efficiency

High efficiency is another advantage of CNC turning. Traditional mechanical turning requires the operator to manually adjust the position and speed of the tool, and the processing efficiency is low. The CNC turning can realize automatic operation through pre-written processing program, which greatly improves the machining efficiency. In addition, CNC turning can also be processed in multiple processes at the same time, further improving the machining efficiency.


CNC turning has the characteristics of high degree of automation. In the CNC lathe, through the operation of the computer control system, it can realize the automatic tool change, automatic measurement, automatic correction and other functions. This not only reduces the labor intensity of the operator, but also improves the stability and reliability of the machining.

Good Flexibility and Diversity

CNC turning are also flexible and diverse. By modifying the processing program, different workpieces can be processed to meet the needs of different products. At the same time, CNC turning can also realize the machining of complex shapes, such as curves, surfaces, etc. This will be able to meet the needs of different parts.

Limitations of CNC Turning

When considering CNC turning as the machining process, the limitations should be considered before making a decision. CNC Turning is mainly suitable for machining symmetrical parts along the axis of rotation. For other parts with asymmetrical shapes, they has to be produced by other machining types. Besides, for parts with uneven sections, CNC turning is also not available, while other machining types such as CNC milling are the proper way to go.

Types of CNC Turning Machines

In fact, the lathe is the typical machine used for turning. However, there are different kinds of these devices, each of which is more suitable for a particular turning operation. There are four different types of CNC lathes available for your machining projects.

Horizontal CNC Lathe

These lathes have all the features of a typical lathe, making them one of the most common machines in a variety of industrial applications. However, they are more suitable for turning and boring operations.

Vertical CNC Lathe

Similar to a horizontal lathe, but the main difference is how it holds the workpiece in place. The material is positioned vertically – starting at the bottom before rotation and cutting occur. As a result, these machines are best suited for operations where space is limited.

Horizontal Turning Center

The horizontal turning center is a closed device with drilling and milling functions. As the name suggests, the turning center has a horizontal orientation on which the tool is mounted, gradually rotating and cutting into the workpiece, and relying on gravity to remove the cut.

Vertical Turning Center

As a combination of a horizontal turning center and a CNC milling machine, it is designed to keep the rotating chuck close to the ground, making it easier to handle large workpieces.

Examples of CNC Turning Parts

Shaft Parts

A shaft is a thin, rod-shaped part that is commonly used in mechanical devices to transmit power and carry loads. When the shaft is turned, the accuracy and surface quality need to be guaranteed, so the machining on the lathe usually uses precision turning and outside diameter turning. Shaft parts are widely used in machine tools, bicycles, automobiles, ships and aerospace and other fields.

Cylindrical Parts

Cylindrical parts are one of the most common parts types in CNC turning. Typical examples of machined cylindrical parts include: propellers, hydraulic cylinders, cylinders, bearings, flanges, cams and cranks. The machining of cylindrical parts needs to master the selection and adjustment of lathe tools, while ensuring accuracy and surface quality.

Disk and Sleeve Parts

Disk and sleeve parts are another common type made by CNC turning, mainly including gears, connecting rods, plain bearings and pump bodies. When machining of these parts, the tool selection and machining sequence should be paid attention to.

Other Parts

In addition to the above types of parts, CNC turning can also be used to machine various transmission parts, structural parts and connectors. Typical parts are like nuts, bolts, pins, pins and flanges. The machining requirements of these parts are different, we should choose correct machining methods and tools according to the specific drawings.

In short, CNC turning is a widely used machining method, can be used to creat a variety of parts. These parts are widely used in machinery manufacturing, automotive, aerospace, engineering machinery and shipbuilding and other fields.

Alternative Manufacturing Methods

CNC Milling
CNC Milling - Alternative CNC Turning Manufacturing Method

Similar to CNC turning, CNC milling is a subtractive manufacturing process, in which a rotating cutter removes material from a stationary workpiece. By comparison, CNC turning is limited to creat cylindrical shapes. While CNC milling is more versatile, it allows for creating complex shapes. This process is particularly suitable for producing prototypes, molds, and parts with intricate designs. Unlike CNC turning, CNC milling can handle a broader range of shapes and designs. So when intricate shapes or multi-axis machining is required, CNC milling is an ideal alternative manufacturing method.

Investment Casting
Investment Casting - Alternative CNC Turning Manufacturing Method

Investment casting is a manufacturing method for creating metal parts in several steps. The investment casting process starts from creating a wax pattern of the desired part, coating it with a ceramic shell, and then melting away the wax to leave a hollow shell. Molten metal is then filled into the shell, after cooling, the solid metal parts are formed. CNC turning is a subtractive machining process, while investment casting is a form of additive manufacturing. Investment casting is particularly advantageous when producing small, detailed components with fine surface finishes. It allows for the production of intricate and complex geometries that might be challenging or impossible to achieve by CNC turning process. For example, you can consider stainless steel investment casting as the alternative process when CNC turning can not shape out the stainless steel parts.

Forging - Alternative CNC Turning Manufacturing Method

Forging is a manufacturing process that involves shaping metal by applying localized compressive forces. Unlike CNC turning, which removes material to achieve the desired shape, forging works by deforming the metal through the application of pressure and heat. This method is excellent for producing strong and durable components, as the forging process aligns the grain structure of the metal, enhancing its mechanical properties. Forging is particularly well-suited for large-scale production of parts such as automotive components, aerospace components, and certain industrial tools. The absence of material removal distinguishes forging from CNC turning and can result in improved strength characteristics.

Contact CFS Machine Shop for CNC Turning Services

CFS Machine shop is a high-quality casting and CNC machining company that offers our clients a wide range of services. We have in house CNC machining capabilities including CNC turning. When you are sourcing a reliable partner for your axisymmetric components, contact us for CNC turning services. We can also provide an alternative manufacturing method when CNC turning is not so cost effective.

Contact us today and send us your CAD drawings to cathy.sales01@cnool.net, we will go back to you with a free quote shortly!


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