In the manufacturing and processing industry, CNC machining is a common process. It can be used to process many different kinds of materials. In this blog post, we will discuss 7 of the most common materials that are precision CNC machined.
What is Precision CNC Machining?
CNC machining is a process where a programmed machine moves cutting tools to shape, cut or finish materials. This can be done with a high level of accuracy and consistency when compared to manual operations. Precision CNC machining is a type of CNC machining that requires very accurate tooling and programming to produce parts with high accuracy and tight tolerances.
How Does Precision CNC Machining Work?
The process of precision CNC machining begins with programming a computer to control the cutting tool. The programmed machine then moves the cutting tool over the material being worked on according to the programmed instructions. Specialized software is often used to ensure that each part meets very tight tolerances and accuracy requirements. This process can be repeated quickly, allowing for fast and efficient production of complex parts.
Types of Precision CNC Machining
(1) Rough CNC Machining
First, Excavate most of the processing allowance for each processing surface, process the refining benchmark, and mainly consider improving the productivity as much as possible.
(2) Semi-finished Product
Possible defects after rough processing, to prepare for surface finishing, require a certain processing accuracy, to ensure the appropriate finishing margin, to complete the secondary surface processing.
(3) Precision CNC Machining
At this stage, the use of large cutting speed, small feed and cutting depth, and the removal of the finishing margin left by the previous process, so that the precision aluminum die-casting surface meets the technical requirements of the pattern.
(4) Ultra-precision CNC Machining
The machining accuracy is 0.1-0.01μm, and the surface roughness is ra≤0.001μm. The main processing methods are precision cutting, fine mirror grinding, precision grinding, polishing, and so on.
Materials of Precision CNC Machining
CNC Machining Materials #1: Aluminum
Aluminum is probably the most widely used CNC milling material . It is well suited for use with CNC machines because it is easy to cut and shape, but can still hold its strength when machined correctly. The ability to process more quickly than other materials makes aluminum a more useful material for CNC processing.
Because of its lightweight, non-magnetic properties, corrosion resistance, and low cost, aluminum is widely used in the production of aircraft parts, car parts, bicycle frames, and food containers.
CNC Machining Materials #2: Stainless Steel
Stainless steel is a very versatile material, relatively light and durable, expanding its application in various industries. Stainless steel can also be heat treated and polished to achieve a high level of surface finish, which is why it’s often used in aesthetically-pleasing products.
It’s easy to machine and is highly corrosion-resistant, making it perfect for many components that are exposed to harsh environments. Stainless steel alloys are impervious to most stains and rust. The material is favored for its strength and corrosion resistance and can be used in anything from surgical equipment to electronic hardware.
CNC Machining Materials #3: Carbon Steel
Carbon steel is also one of the popular materials to consider for CNC machining. It is used in many applications due to its durability and strength. It’s a versatile material that can be machined into different shapes, sizes, and components. The low cost of carbon steel makes it an ideal option for the mass production of parts or components.
It is available in a variety of formulations that you can choose from according to your application requirements. Due to its durability, safety, long shelf life, affordability, and environmental protection properties, the material is mainly used for CNC machining.
Carbon steel is most frequently used in construction, automotive parts, and machine tools. It can also be used for medical instruments due to its strength and corrosion resistance.
CNC Machining Materials #4: Brass
Brass is a strong material that has good machinability and can be used in many applications. The relatively low cost of brass makes it an ideal choice for mass production. Brass offers excellent corrosion resistance, strength, and hardness properties as well as good electrical conductivity. It is also lighter than copper and much stronger than steel.
The material is commonly used for plumbing, valves, and industrial fasteners. It can also be used in decorative applications due to its good corrosion resistance and shine. Brass is widely regarded as one of the simplest and most cost-effective materials for precision machining services and is chosen to manufacture complex parts that require complex functions.
Because it is easy to process, smooth and clean, Brass is a popular choice for CNC machining because it can easily be cast into intricate shapes and sizes without losing any of its strength or durability. brass also is used in the manufacture of medical devices, consumer goods, electronic hardware and contacts, accessories, commercial products, and more.
CNC Machining Materials #5: Copper
Copper is a widely used material for CNC machining due to its good electrical and thermal conductivity, malleability, and corrosion resistance. Its low cost makes it an ideal choice for prototyping and mass production.
It’s also very durable and provides excellent heat transfer properties. Copper is used in the manufacture of medical devices, electrical components, automotive parts, and more. It’s primarily used for machining projects that require tight tolerances, accuracy, and strength.
CNC Machining Materials #6: Titanium
Titanium is a strong and lightweight material that offers superior corrosion resistance and strength. It has excellent heat and fatigue resistance, making it perfect for use in extreme environments. The material can also be machined into incredibly small components with tight tolerances.
It’s primarily used in the aerospace industry due to its weight, strength, and corrosion resistance. Titanium is also used in medical equipment and implants due to its biocompatibility and non-toxic properties. It can also be used to make consumer products such as sporting goods, jewelry, and more.
CNC Machining Materials #7: Plastics
CNC Machining Plastic is one of the main ways to make hand plate models at present, mainly ABS, PC, PA, PMMA, POM, and other materials into the physical samples we need.
The plastic sample of CNC Machining has the advantages of large molding size, high strength, good toughness, and low cost, it has become the mainstream way of hardboard production.
Conclusion
These 7 materials play a vital role in the precision CNC machining industry. Each material offers its unique benefits depending on the application and desired outcome. By understanding the different properties and characteristics of each material, you can make informed decisions on which one is right for your project.
FAQs
1. What are the best materials for CNC machining if the parts need to be both durable and lightweight?
When you need parts that can hold their strength without adding bulk, a few materials stand out. Aluminum alloys, especially aluminum 6061, are widely used because they’re easy to machine, resistant to corrosion, and lightweight enough for aerospace and automotive parts. The balance of ductility and high strength makes them a common pick for both prototypes and large production runs.
Titanium is another strong option. It’s tougher to machine, but you get excellent performance in high-stress applications. Then there’s PEEK and polycarbonate—both thermoplastics. These materials can take a hit (literally), resist high temperatures, and stay stable under pressure. That makes them useful when you want machined parts that feel like metal but weigh a lot less.
If weight, functionality, and performance all matter, you’re usually looking at some combination of these materials.
2. Which materials are best for resisting corrosion in CNC-machined parts?
Stainless steel is the top pick when your parts need to stand up to moisture, chemicals, or other corrosive environments. It’s common in medical devices, marine parts, and structural components for that reason. It holds up well and gives you a solid surface finish right off the machine.
Aluminum is also a decent option. On its own, it resists corrosion, but when you go with anodized aluminum, the added layer gives even more protection. That’s especially helpful if you’re also looking for good aesthetics or added wear resistance.
For plastic options, look at PTFE (Teflon), PVC, or HDPE. These materials hold up well against chemicals and water and are often used in bushings, seals, and pipe systems. If your part will be exposed to harsh conditions, material selection can’t be an afterthought—it’ll determine how long that part actually lasts.
3. Can CNC machining be used to make high-performance parts for the automotive industry?
Definitely. CNC machining is used all over the automotive world—from engine blocks to small connectors. Metals like carbon steel, tool steel, and aluminum alloys bring the mechanical properties you need for strength, reliability, and precise fit.
On the plastic side, materials like ABS, Delrin (POM), and HDPE are common. They’re used for things like brackets, panels, and custom injection molding inserts. These plastics offer impact resistance, low friction, and are easy to machine accurately.
For parts that sit near heat or chemicals, like in an engine bay, PEEK and PTFE hold their shape and performance without breaking down. Choosing the right material here isn’t just about durability—it’s also about safety and long-term use.
4. What materials work best for CNC machining prototypes that need to match production parts?
Good prototypes don’t just look right—they behave like the final product. For early-stage testing, ABS, polycarbonate, and acetal (Delrin) are good choices. They’re affordable, easy to work with, and hold up well for form and fit testing. Delrin, in particular, adds dimensional stability and wear resistance, which helps when testing parts with movement or friction.
If your end-use part will be metal, don’t skip the metal during prototyping. Carbon steel, tool steel, and aluminum 6061 are solid stand-ins. Using the same material lets you evaluate tensile strength, abrasion resistance, and how well the part meets tight tolerances.
That way, when you shift to production, you’re not guessing how your design will perform. You already know.
5. What materials are best for CNC machined parts that will be exposed to high heat?
When parts are operating near heat sources—like in engines, exhaust systems, or aerospace assemblies—you need materials that won’t warp, crack, or lose strength over time.
On the plastic side, PEEK, polycarbonate, and PTFE handle high temperatures while still maintaining their mechanical strength. They also offer strong chemical resistance and thermal conductivity, making them reliable in demanding spots.
If you’re working with metals, stainless steel and titanium are go-to materials. Both maintain structural integrity under heat, and tool steel is worth considering too if abrasion resistance is part of the job.
The right call depends on your full list of requirements—tolerances, weight, environment, cost, and more. But if heat is a major factor, your material selection needs to reflect that from the start.