CNC Turning Process Step By Step:Expert Guide

CNC Turning Process Step By Step:Expert Guide

Science and technology are always advancing. CNC turning is now used more widely in manufacturing. It is precise and efficient. It meets the growing needs of modern manufacturing. So, it has an irreplaceable role in machinery manufacturing. This article introduces CNC turning. It covers its overview, process steps, pros, cons, and uses. This will help you choose the right processing program.

Table of Contents

What is CNC turning?

CNC turning refers to a machining process in which a computer system controls the machine tool to remove material from the workpiece. It is mainly used for machining rotating parts. These include shafts, disks, bushings, and other parts with rotating surfaces. Because it uses computer programming to control the feed and movement of tools on the machine, it can achieve high machining accuracy and surface quality. In the whole cutting process, the workpiece is fixed on the Z-axis and does rotary rotation. The cutting tool moves under the control of the G-code to achieve the shape and size of the workpiece.

The basic components of CNC turning equipment include the following:

main machine part: this is the core of the CNC lathe, including the bed, spindle, tool holder feed system, and other key components. The bed is the basic structure to support the whole machine tool, and the spindle is responsible for driving the workpiece for rotary motion. The tool holder is used to install and fix the cutting tool. The feed system controls how the tool and the workpiece move relative to each other.

Tool holder part: The tool holder is the part for installing and cutting tools, CNC lathe can usually be equipped with multiple tool holders for different types of cutting operations. The tool holder has a tool holder seat, tool holder slide, and toolbar. These parts work together to ensure that the tool can cut accurately and stably.

control system: the control system is the “brain” of the CNC lathe, used to control the movement of the machine tool and cutting operations. It is based on a preset program and parameters. Servo motors and other actuators control it. They achieve the spindle speed, feed rate, depth of cut, and other machining parameters with precision.

Auxiliary equipment: Auxiliary equipment includes a cooling system, lubrication system, chip removal device, etc. These equipment are vital to ensure normal operation and prolong the service life of the machine tool. The cooling system reduces the heat in cutting to protect the workpiece and tool from overheating. The lubrication system keeps the machine well-lubricated to reduce wear and failures. The chip removal device quickly clears waste chips from cutting to keep the work area clean.

In addition, the CNC lathe also has input/output devices. It also has a spindle servo drive system, a feed servo drive system, and a position detection system. These systems allow it to interact with the operator, precisely control the machine, and detect the machining position.

In short, a CNC lathe has all the parts. It has a mechanical structure, control system, drive device, and extra equipment. These parts work together to automate and make precise the processing of the workpiece.

Thread cutting process on a metal workpiece

CNC turning process details and processing steps

Process details

The main CNC turning process has external turning, internal turning, face turning, thread turning, and other types of processing. You can select and combine these types of machining. Do it based on the shape of the workpiece and demand.

External turning: external turning is the most basic CNC turning process, almost all of the workpiece processing will be external cutting. First of all, choose the external turning tool suitable for the workpiece material (such as carbide tools or high-speed steel tools), and then move the rotating workpiece along the Z-axis direction, at the same time, the turning tool moves perpendicular to the direction of the workpiece and feeds a certain depth, and finally ensure that the size of the external circle size and surface quality to meet the requirements of the drawings.

Internal turning: CNC internal turning is a CNC lathe on the inner surface of the workpiece cutting technology, but also CNC turning is the most common processing technology, generally choose the internal turning tool processing workpiece diameter hole.

Face turning: In face turning, the purpose is to make the workpiece the right size. Face turning keeps the workpiece’s Z-axis still. The tool feeds radially until the end of the face. This gets the size needed in the drawings.

Thread Turning: Choose a suitable thread-turning tool. It moves along the edge of the rotating workpiece and cuts the material to form threads. Choose the suitable cutting speed and feed speed, cut the threads one by one, and gradually reach the final thread depth.

Anodized aluminum parts in various colors after CNC turning

Machining steps

Turning using CNC turning process generally includes the following machining steps:

Preparation of the program: first of all, according to the parts drawings, use CNC programming software (such as CAD / CAM software) to prepare CNC programs, CNC programs are generally G code (geometry code) and M code (machine function code) two.

Material Selection: Before selecting the turning material, ensure the size, shape, and surface quality of the material meet the processing requirements. Then, do the needed pretreatment, such as annealing and tempering. When selecting materials, you must consider cutting, mechanical, and heat treatment performance. You must also consider other factors.

Workpiece installation: Choose a fixture that fits the workpiece’s shape and size, such as a three-jaw chuck, four-jaw chuck, spring collet, or special fixture. Secure the workpiece to the lathe’s spindle to ensure alignment and stability.

Tool selection: the selection of tools has an important impact on the machining quality and efficiency of the CNC turning process. According to the processing needs choose the appropriate tool and install it in the tool holder, set the initial position, and adjust the cutting amount and cutting speed of the tool to ensure that the cutting process is stable and efficient.

Turning operation: after several sides and several steps have been prepared, it is now necessary to carry out the workpiece test cutting processing, load, and start the CNC program prepared and completed in advance, the machine tool is processed according to the preset instructions. The tool moves relative to the workpiece. It does roughing and finishing. It removes extra material and forms the desired shape and size.

Quality control: Use simple gauges (e.g. calipers, micrometers) or precision testing equipment (e.g. CMM, universal tool microscope, etc.) to test the dimensions and surface quality of the workpiece. At the same time, take the steps needed to protect the stability and safety of the machining process. Do this by improving equipment maintenance and operation.

As the CNC turning process involves several aspects of technology and operation points. One needs deep understanding of process traits. They must choose the right machining and materials. They must also select and adjust tools and fixtures, and improve quality control. This ensures the CNC turning process is efficient, stable, and reliable.

CNC milling machine drilling precise holes in a metal component

Advantages and disadvantages of CNC turning

CNC turning is now widely used in the manufacturing industry. CNC turning has many advantages compared to manual turning. But, it also has some disadvantages. The following are the main advantages and disadvantages of CNC turning:


High machining accuracy: The CNC lathe is controlled by a computer. It can achieve micron-level accuracy. This ensures the stability of the workpiece’s quality and size.

High machining efficiency: Programming control makes mass production of complex parts efficient. Automatic machining reduces manual operation and intervention, improving production efficiency.

Saving labor costs: CNC turning can be managed by a small number of operators to manage multiple machines at the same time, which reduces the dependence on skilled technicians, reduces labor costs and labor intensity of workers, and also helps to improve the working environment.

Higher degree of automation: The CNC system controls the whole machining process. It automatically regulates tool feed, spindle speed, and other factors. This automation greatly improves efficiency.


Higher investment costs: the need to invest a lot of money in the early stage to buy equipment and programming software, and later maintenance and repair also require a cost, so the whole process requires a lot of money to support.

High technical requirements: CNC turning requires professionals to write CNC programs, so the technical level of the programming staff requires a high level. Especially the program writing of complex parts requires a lot of energy and time.

Lack of flexibility: CNC lathes excel at processing complex parts and mass production. However, manual lathes are better suited for single-piece, small-lot production or situations requiring flexibility, as manual machining can be quickly adjusted and modified.

CNC turning is becoming more important in modern manufacturing. High accuracy, efficiency, and automation make it ideal for mass production and complex parts. However, it also has high cost, high technical requirements, and lacks flexibility. In actual machining, you need to consider production needs, budget, and tech conditions. Only in this way can we better utilize CNC-turning technology to improve production efficiency and product quality.

CNC turning tools and machined components

CNC turning applications

At present, CNC turning is used in various industries, mainly in the following areas:

Aerospace field: Aerospace parts have extremely high requirements for precision and reliability. CNC turning can process parts with complex shapes and high precision automatically. It ensures the parts meet the design requirements for quality and performance. For example, vital parts of aircraft engines, such as blades and guide plates, can be made with high precision by CNC turning. This improves the engine’s performance and reliability.

Automobile manufacturing field: The automobile manufacturing field involves many parts. CNC turning can process them with high precision. For example, the crankshaft, camshaft, and cylinder block are engine parts. The transmission system has gears and shafts. These parts are inseparable from CNC turning.

Medical field: due to the medical industry on the parts higher precision requirements and the existence of many shaft parts, so can use CNC turning processing. For example, scalpels, bone nails, and so on.

Electronic equipment field: some manufacturing equipment is used in a large number of cylindrical parts and shells, so you can use CNC turning to ensure the accuracy of processing. For example, electronic connectors and terminals, bearings and transmission parts, and other parts.

Precision CNC turned automotive parts with surface treatment


CNC Turning tech’s use in manufacturing is growing. It’s changing with tech progress and market shifts, showing many trends. The future will show a trend. It will have intelligence, high precision, efficiency, and green production. It will also have multifunctional integration. These trends boost production efficiency and product quality. They cut costs. They also improve the market power of firms. They drive the upgrade of the manufacturing industry. Afterward, if you need CNC turning Services, please contact Yonglihao Machinery. We have years of experience and expertise in CNC turning. We will give you professional services and complete solutions.


CNC turning works with many materials. These include metals, such as aluminum, steel, and brass. They also include plastics, composites, and other special materials.

CNC turning can achieve very high machining accuracy. It has a dimensional accuracy of ±0.01 mm (10 microns) or better. High precision CNC lathes can achieve even higher dimensional accuracy of ±0.001 mm (1 micron) or so. It depends on the machine and tools used.

Yes, CNC turning technology is well suited for small-scale production. CNC turning is efficient and repeatable. It can provide high-precision machining and meet diverse product needs.

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