Different materials have different properties. CNC Machining material not only affects the performance and lifespan of your product, but also directly influences your production cost, production efficiency, and the final product performance.
Therefore, the selection of materials is the foundation for you to develop and design products. This article will help you better explain different types of CNC machining materials.
Different Kinds of CNC Machining Materials For Your Application
Aluminum
Aluminum is definitely one of the most widely used materials in CNC processing. It is commonly applied in electronic products, enclosures, bicycle parts, aerospace components, and etc.
The most common models are 5052, 6061, 6063, and 7075. Aluminum of the 6 series has the best anodizing effect. The surface treatments of aluminum materials are also quite diverse, including anodizing, sandblasting, beadblasting, powder coating, electrophoresis, etc.
You can choose the corresponding surface treatment method according to the appearance or functional requirements of your product.
Stainless Steel
Stainless steel is one of the commonly used structural CNC machining materials. The common types include 303, 304, 316, and 316L.
When you are choosing parts with structural strength and corrosion resistance requirements, stainless steel will be a very reliable option, especially suitable for industrial equipment, mechanical structures, and functional parts that require long-term stability.
If your product has high requirements for surface appearance, stainless steel can also be polished or mirror-polished according to the roughness you marked in drawings.
Due to the relatively low machinability, a lower cutting speed and higher tool wear are usually required when CNC machining , so the overall processing cost is usually higher than that of aluminum alloy materials.
Brass
Brass is also a very easy CNC machining material, but its major drawback is its price. The recent fluctuations in prices have led to extremely unstable product prices, which is another headache-inducing issue for you.
Brass is widely used in connectors, decorative pieces, and electrical components.
Because brass is easy to oxidize, if your product has a high requirement on appearance, we usually recommend that you apply sandblasting and a clear coating. This will effectively prevent the appearance of brass parts from oxidizing.
Copper
Copper is relatively ductile and has a tendency to deform during machining. Compared with brass, copper requires tighter machining control. However, its key advantage lies in its excellent electrical and thermal conductivity, which makes copper widely used in custom heat sink applications.
Similar to brass, its price is also unstable and the cost of raw materials is relatively high. If your project budget is limited but you still want to verify your design, you can first start with a prototype for testing.
Titanium
Titanium is a very difficult material for CNC machining. It is widely used in fasteners, turning parts, aerospace parts, and some high-end industrial parts.
Due to its poor heat conductivity, titanium parts usually result in longer processing cycles, higher tool costs, and stricter process control requirements in actual production.
Carbon Steel
Carbon steel is a cheap CNC machining material. But it is easy to rust.
They are widely used in mechanical structural components and industrial parts. If your order quantity is large and has a great limit in budget, carbon steel might be a good choice for you.
ABS
ABS is also a very easy-to-process plastic material. Due to its relatively lightweight, it is one of the materials commonly used for CNC enclosure parts. Plastic materials have a limited surface finishing compared to metals.
PC
Polycarbonate is a very transparent material. During the processing, it is easy to deform. However, our rich experience can help you effectively control the project. The PC keyboard case is also quite popular in the application of electronic components.
PMMA
PMMA is also known as acrylic. Usually, when processing acrylic, there will be significant tool marks left on the surface. Given its high transparency, we can use the flame polishing to reduce the tool marks on the surface and ensure the aesthetic appearance of your custom acrylic parts.
POM
The Pom material is highly rigid and is commonly used in high-precision structural components. Whether it’s for cylindrical parts with strict concentricity requirements or milling parts with relatively high tolerance requirements, we can perfectly meet your project needs.
Nylon
Nylon material is renowned for its high wear resistance and tensile strength, and it can withstand medium-load structural components. If you want to further enhance the strength and rigidity of the parts, we offer fiberglass-reinforced nylon materials for your choice.
UHMW-PE
UHMW-PE is a type of polyethylene with ultra-high molecular weight and is highly suitable for guide rail sliders as well as components of the conveying system.
PEEK
The raw material cost of Peek material is very high. It is resistant to high temperatures, so it is usually used in medical and aerospace-grade parts.
We recommend PEEK only for high-temperature or high-performance applications due to its high material cost.
Differences Between Different Types Of CNC Machining
Just as we have previously described the various materials, each material has its specific application. If you are unsure about the processing difficulty and the main application of these materials, then I hope the table below can provide you with a good understanding.
CNC Machining Material Comparison Chart
| Material | Key Properties | Machinability | Surface Finishing Options | Typical Applications | Cost Level | Key Notes |
| Aluminum (5052 / 6061 / 6063 / 7075) | Lightweight, good strength, corrosion resistant | ★★★★★ | Anodizing, sandblasting, polishing, powder coating, electrophoresis | Electronics, enclosures, aerospace, bike parts | Medium | 6061/6063 best anodizing performance |
| Stainless Steel (303 / 304 / 316 / 316L) | High strength, corrosion resistant | ★★★ | Polishing, brushing, mirror finish | Industrial parts, mechanical structures | Medium–High | Higher tool wear, slower machining |
| Brass (C360 / C260) | Good machinability, electrical conductivity | ★★★★★ | Polishing, coating, anti-oxidation coating | Connectors, decorative parts | High (price fluctuates) | Easily oxidizes over time |
| Copper (C110 / C101) | Excellent thermal & electrical conductivity | ★★★ | Polishing, coating | Heat sinks, electrical components | High | Soft material, deformation risk |
| Titanium | High strength-to-weight ratio, corrosion resistant | ★★ | Sandblasting, polishing, limited anodizing | Aerospace, medical, fasteners | Very High | Low thermal conductivity increases tool wear |
| Carbon Steel | High strength, low cost | ★★★★ | Electroplating, black oxide, painting | Structural parts, industrial components | Low | Requires anti-rust surface treatment |
| ABS | Lightweight thermoplastic, impact resistant | ★★★★★ | Painting, coloring | Enclosures, prototypes | Low | Limited heat resistance compared to metals |
| PC (Polycarbonate) | Transparent, impact resistant | ★★★ | Polishing, dyeing, controlled sandblasting | Electronics housings, keyboard cases | Medium | Risk of deformation during machining |
| PMMA (Acrylic) | High transparency, brittle | ★★★★ | Flame polishing, polishing | Display parts, lighting covers | Medium | Crack risk under stress |
| POM | High rigidity, low friction, stable | ★★★★★ | Machining finish, polishing | Precision components, gears | Medium | Excellent dimensional stability |
| Nylon | Wear resistant, tough, flexible | ★★★★ | Dyeing, machining finish | Mechanical parts, gears | Medium | Moisture absorption affects stability |
| UHMW-PE | Ultra-low friction, chemical resistant | ★★★★ | Machining finish | Sliders, conveyor parts | Medium | Lower precision capability |
| PEEK | High temperature resistance, chemical stability | ★★ | Machining finish | Aerospace, medical, high-performance parts | Very High | Premium engineering polymer |
How To Select The Right CNC Machining Material For Your Application
When you start a new CNC processing project, the choice of materials is often as important as the design of the drawings. Before CNC material selection, you need to comprehensively consider multiple factors such as mechanical properties, usage environment, budget and processing feasibility.
Mechanical Properties
Mechanical properties are usually one of the first factors to be confirmed when selecting materials. Based on the function and usage of your part, we can generally quickly determine its requirements for properties such as strength, hardness, and wear resistance.
- If the structural component needs to withstand high loads, stainless steel is usually chosen.
- For parts with friction or repeated contact, engineering plastics such as nylon are commonly used.
- In cases of guide rails or sliding structures, UHMW-PE is more frequently used, mainly due to its low friction coefficient.
Corrosion Resistance
Considering the anti-corrosion property, the most recommended material is stainless steel. If you choose other metal materials as your preferred choice, then you need to select the corresponding surface treatment to deal with it.
Machinability
In mass production projects, machinability is often an important factor for you to consider when choosing materials.
- Aluminum alloys and brass have good processing performance.
- Stainless steel has relatively higher processing difficulty.
- Some plastic materials are easy to process, but deformation issues need to be noted.
Cost & Budget
Regarding your project and budget, we can assist you in analyzing the most feasible and suitable materials for the project.
While meeting the functional requirements, the following factors can be comprehensively considered:
- Raw material cost
- CNC processing cost
- Surface treatment cost
- Post-installation maintenance cost
For instance, for cost-sensitive projects, aluminum alloys and engineering plastics usually have more advantages over stainless steel and titanium alloys.
Surface Finish Requirement
If your part has strict appearance requirements, the surface treatment method will directly affect the choice of materials.
- Aluminum alloys are usually suitable for anodizing, and you can choose the corresponding product color according to your preference.
- Stainless steel can be treated with processes such as sandblasting, brushing and polishing.
- Brass and copper can have their appearance and corrosion resistance improved through electroplating.
- Some plastic materials can also achieve better appearance effects through painting or polishing.
Therefore, before confirming the materials, it is recommended to first determine the final desired surface effect.
Manufacturability & Geometry
Before making the material selection, we also need to conduct a comprehensive review of your drawings.
- For thin-walled structures, the material’s rigidity and deformation risk should be taken into account.
- For large-sized parts, the limitations of raw material specifications should be considered.
- For deep cavity structures, the reachability of the cutting tools should be considered.
- For high-precision parts, the stability of the material after processing should be considered.
If you are unsure about how to make the selection, we will provide DFM feedback to assist you.
FAQ
What is the best material for CNC Machining?
In fact, there isn’t a material which can cover all requirements. The material which can fully meet your requirement I think is the best material for you. But aluminum is the most common material you use in different applications.
How does CNC material selection impact machining performance?
Different materials have different machining performance. If you choose one material such as stainless steel which is hard for machining, it will cost more and take longer time.
What is the cheapest CNC machining material?
Normally, plastics are cheaper than metal materials. But there is no absolutely cheapest CNC processing material, because the final cost of a part is not only determined by the price of the raw materials, but also affected by factors such as processing time, processing difficulty, surface treatment, and order quantity.
To be simple, if your primary goal is to control costs, 6061 aluminum, carbon steel, ABS and POM are usually the most worthy CNC processing materials to consider as priorities.
Can plastics be used effectively in CNC machining?
For plastic materials, ABS and POM are usually cost-effective choices. These materials have reasonable prices, are easy to process, and can meet the requirements of most industrial and consumer products.
Which CNC materials hold the tightest tolerances?
For metal materials, aluminum alloys (such as 6061), brass, stainless steel (such as 303 and 304), and tool steel can usually achieve high machining accuracy.
For plastic materials, POM (Delrin), PEEK, and some engineering nylon have good dimensional stability.
Generally, most precision CNC parts can be controlled within the range of ±0.01 mm to ±0.05 mm.
What are the best CNC machining materials for aerospace?
7075 Aluminum, titanium and peek are 3 common best materials for aerospace parts.
What is the difference between 5052 vs 6061 vs 7075?
5052 aluminum alloy has excellent corrosion resistance and forming properties.
6061 aluminum alloy has the most balanced overall performance, featuring good strength, machinability, corrosion resistance, and cost advantages. Therefore, it is one of the most widely used aluminum materials in CNC processing.
7075 aluminum alloy has the highest strength among the three and is commonly used in aerospace, high-performance mechanical parts, and lightweight structural components.
If you want to do anodize parts, we recommend 6061 instead of 5052 and 7075.
Final Thoughts
Yecheng CNC is your reliable machining partner for all these 13 different types of materials. And we have our in-house anodize production line. Therefore, we have advantage in parts which have high requirements on the performance such as enclosures. Welcome to send us inquiries for DFM feedback.
