What Is CNC Machining & How Does It Work? (A Comprehensive Guide)

What Is CNC Machining & How Does It Work?

What is CNC Machining & How Does It Work? – In the Computer Numerical Control (CNC) machining process, production equipment and tools are moved according to pre-programmed computer software. The procedure may be used to operate a variety of complicated machinery, including mills, CNC routers, lathes, and grinders. Three-dimensional cutting jobs may be completed with CNC machining in a single set of instructions.

Basics of CNC Machining?

Understanding the CNC process and how it functions will help you better grasp the challenges associated with properly using your data for a CNC-controlled machining or cutting operation. This little introduction should be useful.

Some Basic Definitions

CNC: Computer Numerical Control – A computer and CAM software are used to automate, control, and observe the motions of a machine using digital data. The machine might be a robot, router, lathe, grinder, welder, sheet metal stamping machine, laser or waterjet cutter, or any number of other devices. The computer is often an on-board specialized controller for bigger industrial machinery. However, the computer can be an external PC for machines that are more suited to hobbies or with certain retrofits. In order to move and control the machine axes and carry out the preprogrammed movements, the CNC controller collaborates with a number of motors and drive components. The advanced feedback system that continuously analyzes and modifies the cutter’s speed and position is often present on industrial equipment.

Desktop CNC: There are a lot of smaller desktop CNC machines designed for model makers and hobbyists. These are often less costly, slower, less accurate, less stiff, lighter, and less rigid than their industrial equivalents, but they work well for milling things made of softer materials like plastic, foam, and wax. Some desktop computers may operate quite similarly to a printer. Others may even have specialized CAM software and their own closed command system. A few will also take input in the form of regular G-code. Certain desktop industrial standard machines have specific controllers for performing fine tiny operations.

CAM: Computer-Aided Machining or Manufacturing – This is the process of using different software programs to generate toolpaths and NC code for a CNC-operated machine based on data from 3D computer models (CAD). The combination of the two is frequently referred to as CAD/CAM.

It should be noted that CAM only generates code for the CNC machine to follow. Additionally, it does not import your CAD model and automatically generates the appropriate NC code. In order to execute the program, create machining strategies, and know which tools and operations to employ in each circumstance to produce the best results, CAM programming, like 3D modeling, requires knowledge and expertise. While there are certain straightforward programs that a novice user can pick up and use without too much trouble, more complex models require time and financial commitment to become skilled.

NC code: This is a unique, relatively basic computer language that can be understood and used by CNC machines. These languages were first created to enable direct part programming at the keyboard of the machine without needing a CAM application. Along with managing other machine operations like spindle and feed speeds and coolant, they instruct the machine on what actions to do one at a time. The most widely used language is G-code, often known as ISO code, a basic alphanumeric programming language created in the 1970s for the first CNC machines.

Postprocessor: Although G-code is regarded as the industry standard, individual manufacturers are free to change certain components, such as auxiliary functions, making it possible for G-code designed for one machine to malfunction on another. Many machine makers have also created their own programming languages, including Heidenhain and Mazak. Therefore, there is a bridge software component software called a postprocessor to convert the internally determined routes of the CAM software into precise NC code that the CNC machine can interpret. Once properly set, the post processor generates the appropriate code for the selected machine, allowing any CAM system to produce code for any machine theoretically. Postprocessors may come with the CAM system for free or at an additional fee.

What Is CNC Machining & How Does It Work?
CNC machining (Reference: indiamart.com)

How Do CNC Machines Work?

Modern CNC machines are entirely automatic. All they require are digital files that provide information on the tools and cutting trajectories.

To create a certain product, design or machining operations need to use several tools. Machinists are able to create digital tool libraries that connect to the actual machine. These machines are production workhorses because they can swap tooling automatically based on digital instructions.

Designing the components with CAD software is the first step in the CNC manufacturing process. The final part’s requisite size and attributes are determined from the 3D model.

The flow can continue in the same programs because some of these applications are included in CAD-CAM packages. Otherwise, CAM software is used with CAD models. No file translation is required if the CAD and CAM systems are part of the same product family. Otherwise, it is necessary to import the CAD files.

The model is ready for the entire production process thanks to CAM (computer-aided manufacturing) software. It first looks for mistakes in the model. The actual portion is then created using CNC software.

A collection of coordinates that directs the cutting head during the manufacturing process is essentially what the program is.

Selecting the appropriate settings is the third stage. These include things like cutting speed, voltage, and RPMs. The geometry of the part, as well as the equipment and tooling available, all affect the configuration.

Finally, the nesting is decided by the program. Nesting refers to how components are positioned and oriented in relation to raw materials. Maximizing the use of the materials is the goal.

Then, M-code and G-code, which the equipment can comprehend, are created from all of this information.

What Is CNC Machining & How Does It Work?
Working principle of a CNC machine (Reference: timebusinessnews.com)

Types of CNC Machines

CNC Milling Equipment

One of the most popular forms of CNC machining, CNC milling is renowned for its high precision and tight tolerances. After materials are loaded into CNC machines with built-in drilling and cutting tools, the computer will direct the tools as they perform their magic.

While 3-axis CNC milling is frequently the better option for producing more straightforward parts, 5-axis CNC milling is normally better suited to more complicated geometries and is typically completed in a single operation.

CNC Lathe Equipment

Contrary to CNC milling, which involves moving the cutting tools to remove material, CNC turning involves rotating the material while it is being cut. CNC lathe machines have a central lathe that manipulates and pushes the material into the desired location according to computer programming.

CNC Plasma-Cutting Equipment

CNC plasma cutting machines are utilized to cut materials, just as CNC milling machines. They are different from their milling counterparts in that they carry out this process with the aid of a powerful plasma torch that can reach temperatures of up to 50,000 degrees Fahrenheit and cut through tough materials like metal!

CNC Laser Cutting Systems

Contrary to plasma-cutting CNC machines, laser-cutting CNC machines are likewise made to pierce difficult materials, but they do it by using a laser (rather than a plasma torch). Even while these lasers aren’t nearly as powerful as plasma torches, they usually have a greater cutting precision level.

What Is CNC Machining & How Does It Work?
A CNC Laser Cutting System (Reference: china-machining.com)

Electric Discharge CNC Machines

Electric discharge from a CNC machine, commonly referred to as a spark CNC machine, is a unique kind of CNC machine that shapes materials using electrical sparks. Materials are inserted between a top and bottom electrode, and the computer then controls how the component is molded and how much electrical discharge the electrodes create.

Advantages of CNC Machining

CNC machines assist manufacturers in enhancing productivity and accuracy and help lower the risk of human error by enabling them to automate various production operations that would otherwise need to be carried out manually.

Here are 5 significant ways they have changed engineering:

CNC Machining Is Excellent For Producing Lots Of Parts

If you need to produce more mechanical components in larger quantities (from the upper double digits to the 100s), CNC is likely to be the most cost-effective option since it is far less expensive to use CNC machining than 3D printing.

Various Materials May Be Worked On Using CNC Machines

While CNC machines are usually unconcerned with the materials they are cutting, 3D printing primarily focuses on plastics as long as the material is robust enough to avoid deforming or melting under the pressure of the cutting operation. Aluminum, stainless steel, magnesium alloy, zinc alloy, titanium, and brass are the metals that are utilized the most frequently.

CNC Equipment Produces Items Swiftly

You likely won’t be surprised to learn that machines operate more quickly than people do. You may receive the final goods in as little as 5 days when you purchase your CNC machined components from a perfect CNC machine.

CNC Equipment Is Very Precise

A typical CNC tolerance is +/- 0.127mm, and when you utilize the tolerance configurator, you can anticipate precise machining down to +/- 0.005mm, giving you an indication of how exactly they are.

There Are Several Post-Processing And Finishing Choices With CNC Machining

For instance, a CNC machine provides high-quality finishing procedures, including anodizing, polishing, heat treating, plating, powder coating, and more, for the majority of CNC-machined parts.

Limitations of CNC Controlled Machines

CNC machines’ capabilities may be constrained by the sophistication and age of their control and drive systems. The majority of CNC controllers only comprehend circular arcs and straight-line motions. The arcs are often only allowed on the main XYZ planes in many machines. Rotating an axis can be thought of as moving linearly, only in degrees rather than in space. Two or more axes must interpolate (move precisely and synchronously together) in order to produce arc motions or linear movements that are at an angle to the major axis. Also capable of simultaneous interpolation are rotary and linear axes. Five-axis machines require that all five be precisely synced, which is a difficult undertaking.

It is crucial that the machine controller can interpret incoming data quickly, send orders to the drive system, and keep track of the machine’s speed and location. In this regard, older and less costly devices are plainly less competent, much as how an older computer would perform demanding tasks less effectively and more slowly (if at all) than a modern one.

Applications of CNC Machining

No matter what kind of material you work with—wood, metal, or pretty much anything else—you’ve definitely heard of the formidable CNC machine. While we often only think of recent years when it comes to computers, CNC technology has been around since the 1940s.

Since then, CNC technology has advanced significantly and now has a wide range of new applications, as we’re sure you can anticipate. Let’s discuss some of the top applications and advantages of CNC machining.

CNC Machines Are Repeatable 

The main advantage of CNC punching is the ability to produce as many copies of a design as your materials will support after the design has been defined. Once the application is installed, you can simply save it and utilize it whenever you choose, whether you’re creating plaques, carved signs, decorations, or even automotive components.

There are just too many advantages of CNC technology to enumerate, but there are also more applications than we could ever include in one list. Here are a few that you might not be familiar with.

Dental Supplies

It may surprise you to learn that dentists frequently utilize CNC machinery, especially when placing dental crowns.

Although wood and sheet metal are frequently made using CNC machining services, they are capable of producing much more. Even dental crowns and implants may be carved out using CNC software since the technology is very accurate.

The best part about it is how simple it is to set up and how precisely it can produce crowns that fit exactly where they were intended in your mouth. Think again if you believed that the only companies who provided machining services were automakers! This technique has been utilized by dentists for many years.


You may be aware of the debate around 3D printers because of their capacity to produce weapons without serial numbers. However, CNC machines have existed for a far longer time and have always had that potential.

Additionally, CNC machines may even modify rifles to add grips and other attachments. The quantity of material you need to start with is the sole distinction from a 3D printer. However, it is prohibited to make weapons without a license, despite the fact that many different firearm firms produce their products using CNC mills.

The military and defense sector frequently employs CNC manufacturing to produce different types of weaponry and equipment in addition to guns. The entire industry gets a lot of its equipment from CNC production.


Even if it might not come as a surprise, CNC punching can be useful quite a bit when it comes to building. You might not anticipate some of these.

Even the most accomplished carpenters would struggle to match the level of accuracy needed for some works, particularly when working on pre-existing structures.

This level of precision may be required by other trades, such as HVAC professionals, plumbers, and pipefitters. Essentially, CNC technology may give so much more than any other tool, which is the key factor. With the capacity to operate on any material you can imagine, they can perform many functions simultaneously, including those of a router, drill press, jigsaw, table saw, jointer, and even a surface planer. It’s tough to surpass.


This is a wide word since the services provided by CNC technology to the sector are so varied. CNC technology is used in various ways by the aviation, railroad, and automobile sectors since it provides such a wide range of services.

To guarantee that every component of the plane operates as it should while you are thousands of feet in the air, every element must be made with such accuracy. For this reason, the industry has traditionally relied on machining services.

In order to assure safety, railroads and autos must also be constructed appropriately. Automakers must make sure that quality control is their first concern because more than 70 million automobiles are produced each year. There must be uniformity throughout. Because machines can provide greater regularity than people can, CNC services are very useful to the industry.

What Is CNC Machining & How Does It Work?
CNC machines have numerous applications in industry, especially transportation (Reference: china-machining.com)

Development And Research

Prototypes are necessary for R&D across practically every sector, along with some degree of trial and error. That covers physics, chemistry, biotechnology, woodworking, and other subjects. Any notion you have in your brain may be brought to life with skilled accuracy using CNC machining.

Since its beginnings, it has been used to create precise prototypes in practically every industry you can think of, and it still does so today.

Niche Production

In actuality, CNC machines are capable of doing almost anything. A CNC machine can produce practically anything that needs to be made from the right amount of any material.

What other machine could construct a door, a spinning wheel rim, an electronic guitar, and a dental crown in a matter of hours? CNC technology has raised the bar for manufacturing in all specialized fields and fashions and is only becoming better. Whatever your demands are for production, a CNC can meet them.


This post has produced a collection of data on CNC machining, its working principle, applications, limitations, and advantages. You are also encouraged to visit the Linquip website to learn more about these machines, as well as to find providers of additional industrial and commercial items. You can also visit our CNC Milling Machines Suppliers and Companies to find out a complete list of CNC machine products and suppliers.

FAQs about CNC Machining

1. How Does A CNC Machine Work Step By Step?

In order to move and control the machine axes and carry out the preprogrammed movements, the CNC controller collaborates with a number of motors and drive components. The advanced feedback system that continuously analyzes and modifies the cutter’s speed and position is often present on industrial equipment.

2. What Is g-Code and M Code?

The machine control language, often known as M code or G code, governs the whole program. M code governs the machine’s activities, whereas G instructions define locations. Although M stands for many codes, some people refer to it as machine code since it manages specific equipment functions.

3. How Many Types Of CNC Machines Are There?

CNC machines come in eight different varieties: mills, routers, lathes, plasma cutters, laser cutters, water jet cutters, electrical discharge machines (EDM), grinders, and water jet cutters.

4. Is CNC Easy To Learn?

If you have a basic understanding of technical design, computer and arithmetic skills, and manual machining expertise, you may become proficient at writing G-code and 2d-CAM programs in just one week.

5. Can You Teach Yourself CNC?

Given a rudimentary understanding of math and an understanding of how milling functions, learning very basic CNC programming is simple. Usually, you can master this within a few days. While learning advanced CNC programming might take many years, learning intermediate programming abilities can be taught in a year.

6. What Are The Main Components of a CNC Machine?

Three fundamental parts make up a computer numerical control (CNC) system: processing apparatus, often known as a machine tool, a machine control unit, and CNC software, which is a set of instructions.

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