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Basic knowledge of CNC machining
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Basic knowledge of CNC machining

Views: 202     Author: Wendy     Publish Time: 2023-05-18      Origin: Site Inquire

Basic knowledge of CNC machining

Computer Numeric Control (CNC) Machining is one of the most popular manufacturing techniques that use automated tools to generate the needed shapes and parts. What is CNC machining or how it works is a common question that anyone associated with the industry should know about.

The following text will take a look at the basics of CNC machining and briefly discuss its major applications across different industries.

Overview of CNC Machining

CNC machining, controlled by computers, produces high-precision parts and components. In this process, a computer program controls the movement of the cutting tools, which the program controls to remove material from a workpiece to create a finished part.

CNC machining produces an array of parts and components, including those made from metal, plastic, and other materials. The process can also produce parts with complex geometries and high levels of precision, making it a popular choice for applications in numerous industries, including aerospace, automotive, medical devices, and consumer products.

CNC machining offers several advantages over traditional machining methods, including improved accuracy, consistency, and speed, as well as the ability to produce complex geometries and intricate details. It also allows for the use of advanced cutting tools and techniques, such as multi-axis machining and high-speed machining, which can further improve the efficiency and quality of the process.

The History of CNC Machining

The history of CNC machining can be traced back to the 1940s when the first numerical control (NC) machines were developed. Over time, these machines became more widespread and sophisticated. This gave them the capability to fulfill the requirements of a variety of industries including aerospace, automotive, and defense.

However, older NC machines still needed manual input and had limited capabilities.

This all changed with the advent of computers in the 1970s, which revolutionized the field of manufacturing and gave birth to the first CNC machines. The new CNC Machines came with computer controls and could process information more quickly and accurately. With CNC, operators could input data directly into the machine and the machine would automatically perform the required operations.

This was only the beginning of CNC machines as the technology continued to advance over the years. The development of more advanced software and hardware along with the introduction of new material and tooling options meant more possibilities for manufacturing units.

Today, CNC machines are common in multiple industries and are capable of producing a diverse range of products with high levels of accuracy and precision.

How CNC Machining Works?

Contemporary CNC machines focus on minimizing human intervention as much as possible. This ensures consistent and continuous performance, which facilitates smart manufacturing and delivers excellent results.

However, CNC machining operations require careful consideration from the initial design to the final manufacturing. The entire process works in three different steps:


This is the first step where the deliverables are design files in CAD, CAM, and CAE format. Engineers and designers use CAD/CAM packages that assist them in creating the overall design of the part and product, which is then analyzed for their manufacturability. This analysis, sometimes called DFM (Design for Manufacturing) is an integral process as it ensures maximum benefits at the lowest overall cost while catering to the limitations of the available technology.

In most cases, the CAD tools available in the market come with an internal CAM tool, which facilitates the pre-processing and programming, which is the next step in the CNC process.

Pre-processing and Programming

The primary method of communicating with a CNC machine is through G-Codes or M-Codes. CAM packages generate these codes which are basically the navigating map for the cutting tool in CNC machines.

In most cases, CNC machinists won’t have to intervene in the operations or pre-processing if the design is according to the DFM standards. In case it’s not, some intervention might become necessary to ensure excellent performance.

This is a general step that is common in any CNC machining operation. How much time is needed for the pre-processing is determined by the overall quality of the design process. Programming the G-Codes or M-Codes only need a few minutes.

However, they are dependent on the design. If the overall design is according to the necessary conventions for DFM, the codes would be correct and deliver acceptable results. On the contrary, flaws in the design would result in flawed codes which would naturally deliver unacceptable results.  


The final stage is the actual machining process, which uses the provided codes from the previous step to remove excess material from a block.

Generally, precision machine tools are extremely important but they can’t exactly reproduce the same dimensions as the CAD model. That’s why machinists generally use tolerances, which are different according to the requirements of the industry. The general rule of thumb states precise tolerances would result in higher costs for the manufacturing unit.