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Wondering which material and how it can be used for CNC machining? CNC is a highly precise and repeatable manufacturing process used to prototype and production parts. It is also subtractive, meaning it involves using computer-controlled cutting tools such as drills and lathes to cut material from blocks. The result is professional-quality, mechanically usable components.


Versatility of materials 

One of the biggest advantages of CNC machining is its material versatility. This is because the process can use aluminum and steel alloys as raw materials, as well as various structural metals. It is also used to cut high-quality plastics. Many of these are CNC machined to produce a variety of finishing options. In most cases, this wide range of options provides such flexibility. However, there are so many CNC machined materials that can also be used, which creates an additional dilemma in making your project end-to-end and cost-effective. In this article, we will discuss the various raw material properties in terms of CNC machining and the factors to consider before choosing a particular CNC material. Keep reading to learn how to easily make the best possible product selection.

How do I choose the right semi-finished material for CNC machining? 

Given the wide variety of materials available for CNC machining, there will likely be more than one raw material suitable for a prototyping or manufacturing task. However, finding that one perfect component for a given CNC machining project is the user’s first task. It’s worth asking yourself the questions: Do you need a metal with excellent mechanical properties, such as titanium? Or is speed a priority, leading you to choose easier-to-machine materials such as aluminum or plastics such as Delrin? Or do you simply want a machine-built prototype at the lowest possible price? Below is a sample list of additional considerations you should answer before selecting CNC materials for your project:

What will the part be used for?

Just as CNC machining can process a variety of materials, it is also suitable for producing a variety of parts. Therefore, using the right semi-finished products is the first thing to consider when choosing CNC raw materials. This is because the application will help determine the properties that the CNC material must-have. For example, parts that require insulating properties will prefer plastic. However, metal may be more beneficial to choose due to its tensile strength. While this example may seem simple, most CNC plastics needed for parts must have multiple properties.

What are the operating temperatures of the part environment?

Another important factor to consider before making a final selection is the operating temperature of the environment in which the part will operate. This is because the melting point of the CNC material used must be higher than the operating temperature. Otherwise, the structure of the part may change. It is also important to ensure that the CNC machined raw material can withstand extreme heat changes. Some materials can withstand these spikes in value, but others may show structural changes over time. Another reason to understand a material’s tolerance to operate temperatures is whether it can withstand the heat generated by CNC machining.

Where the part is used 

The operating conditions of parts vary from location to location. For components used indoors, you can accurately determine the temperature and humidity they will be exposed to in the working environment. However, in outdoor environments where the weather is uncontrolled, it is recommended to use moisture and rust-resistant materials while maintaining their structure. Additionally, extreme changes in weather conditions in outdoor environments can distort the structure of individual CNC materials. Of course, it is not always possible to find a raw material that best meets all criteria. The strongest ones for processing are rarely the cheapest. Additionally, choosing a higher strength may result in reduced chemical resistance or other properties. However, after answering these questions, we should be able to identify the most important specification elements that our chosen CNC machining material must-have. The next step is to identify CNC materials that can match our ideals. 

Overview of different CNC materials

The quickest and easiest way to determine the best and most appropriate material for CNC machining is to consult with an expert. After reviewing your project outline, he or she can help you make decisions about raw materials, fulfillment processes and based on your goals, budget, and time frame. However, if you want to get a short list of potential CNC machining materials in advance, check out the options available. From versatile aluminum alloys to specialty engineering plastics. Here are some materials that are compatible with CNC machining:

Cast metals 

One of the main reasons for the popularity of CNC metal casting is its compatibility with different types of metals. Precision parts for CNC machining can be made from a variety of materials. Some of these are listed below.

Stainless Steel

Stainless steel (SS) is by far the most common type of metal used in precision CNC manufacturing. Valued for its corrosion resistance and strength, this raw material is found in everything from surgical equipment to electronics and more. The metal is known for its versatility, durability, and lightweight, which expands its use in a variety of industries. 

Carbon steel

This is another popular metal for precision machining. It comes in various forms and can be selected according to the requirements of the application. Carbon steel has been chosen for its affordability, durability, long service life, and environmental friendliness. It is also known to provide a high level of machinability and weldability while maintaining high strength.

Aluminum alloy

Aluminum alloys are probably the most popular choice for CNC metal casting. Due to its high processability, corrosion resistance, and lightweight, it is widely used in the manufacturing of automotive parts, food containers, bicycle frames, aircraft parts, as well as many other fields. 

Nickel-based alloy 

Like stainless steel, nickel-based alloys are preferred because of their excellent corrosion resistance. Nickel is combined with zinc, iron, manganese, copper, and chromium to achieve the desired effect. High nickel alloys are often used in chemical processing applications.

Copper Alloy material

Copper-based alloys have high corrosion resistance, making these metals an excellent choice for long-term use. Brass is one of the most popular copper-based alloys. It is considered one of the easiest and most cost-effective metals to use in CNC metal casting services and is chosen for manufacturing complex parts that require intricate features. 

White iron material

It is known for its high compressive strength and excellent abrasion resistance. It also retains its ductility for a specific period after exposure to extreme temperatures. Some types of white iron contain high levels of chromium to further improve performance in high-temperature applications.

Gray iron material

This is a type of iron known for its appearance and color due to the graphite cracks in the material. Depending on the grade of this metal, different levels of strength and workability can be achieved. Grey iron is used where stiffness is more important than the tensile strength of the component, such as electrical boxes, decorative castings, pump housings, etc. 

Ductile cast iron material

This raw material has a higher tensile strength than grey cast iron, making it suitable for many different market segments. Commonly known as ductile iron, it is known for its elongation, wear resistance, hardness, and fatigue resistance due to the spherical structure of the metal.

Copper sheet material

In addition to aluminum and steel, metals such as brass, copper, titanium, and zinc can be machined, giving engineers a wider range of physical properties for parts. For example, copper is an excellent conductor. This characteristic makes it suitable for making electrical parts. 

Polyacetal plastic material

CNC machines are also capable of cutting plastics. In most cases, these raw materials may be preferred due to cost, electrical insulation, or other reasons. When the final part is manufactured by injection molding, plastic is often a suitable material for prototyping.


After reading this article, it becomes clear that CNC machining is a manufacturing process that can be adapted to a wide variety of applications in diverse business fields. Because of this versatility, you may one day be faced with the choices described above yourself and later struggle with every aspect of the manufacturing process. Choosing materials is not an easy task. Metal and plastic materials, or other products must meet the factors that the production assumes. For example, the use of the material, i.e. whether it is used as 3D printing, or it has to be dimensionally stable. When choosing the right material, we also need to know what is the strength to-weight ratio or dimensional stability. Choosing the right material is an extremely important factor that affects the entire manufacturing process.