CNC machining is a term commonly used in manufacturing and industrial applications, but exactly what does the acronym CNC stand for and what is a CNC machine?
The term CNC stands for \’computer numerical control\’, and the CNC machining definition is that it is a subtractive manufacturing process that typically employs computerized controls and machine tools to remove layers of material from a stock piece known as the blank or workpiece and produces a custom-designed part. This process is suitable for a wide range of materials, including metals, plastics, wood, glass, foam, and composites, and finds application in a variety of industries, such as large CNC machining and CNC machining aerospace parts. When speaking in terms of the machine itself, the CNC machine definition is that it represents the actual programmable machine that is capable of autonomously performing the operations of CNC machining. Note there is a difference between the process and the machine.
Subtractive manufacturing processes, such as CNC machining, are often presented in contrast to additive manufacturing processes, such as 3D printing, or formative manufacturing processes, such as liquid injection molding. While subtractive processes remove layers of material from the workpiece to produce custom shapes and designs, additive processes assemble layers of material to produce the desired form and formative processes deform and displace stock material into the desired shape. The automated nature of CNC machining enables the production of high precision and high accuracy, simple parts, and cost-effectiveness when fulfilling one-off and medium-volume production runs. However, while CNC machining demonstrates certain advantages over other manufacturing processes, the degree of complexity and intricacy attainable for part design and the cost-effectiveness of producing complex parts is limited.
While each type of manufacturing process has its advantages and disadvantages, this article focuses on the CNC machining process, outlining the basics of the process, and the various components and tooling of the CNC machine (sometimes incorrectly known as a C and C machine). Additionally, this article explores various mechanical CNC machining operations and presents alternatives to the CNC machining process.