Ultimate Guide for Brass CNC Machining
By Lucas Lo | Updated: August 28, 2024
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When searching for a reliable and stunning material for CNC machining, go for metal with properties. Brass is one of the best materials to consider. It is not only common in day-to-day uses but very popular in machining.
Below is a comprehensive guide about CNC brass, the advantages of brass CNC machining, surface finishes, and post-processing options, and tips for brass CNC machining.
What is CNC brass?
Brass is a name used to describe various copper-zinc alloys. The alloys differ by elements present such as iron, aluminum, and lead as well as the amount of zinc.
Today, brass is among the most used materials. It is perfect for day-to-day usages, musical instruments, and jewelry usages. In addition, it is used in the manufacturing industry due to its excellent mechanical properties.
Brass is a soft alloy since it is composed of copper and zinc. In addition, it is easy to mold, stamp, and machine. Due to its durability, excellent ductility, high resistance to rust, and thermal conductivity, brass has become a common product.
Based on its use, brass might contain tin, lead, nickel, magnesium, or chromium. And thanks to its copper content, the brass is electrically and thermally conductive thus preferred in CNC machining.
Also, the presence of leads boosts machinability, making brass among the most machinable copper alloys. In CNC machining, brass is one of the most used materials.
Brass Grade Chart
Brass is an alloy composed primarily of copper and zinc, with other elements added in varying amounts to enhance specific properties.
Brass Grade | Composition |
C260 | 70% Copper, 30% Zinc |
C360 | 61.5% Copper, 35.5% Zinc, 3% Lead |
C385 | 57% Copper, 40% Zinc, 3% Lead |
C464 | 60% Copper, 39% Zinc, 1% Tin |
C230 | 85% Copper, 15% Zinc |
C260
Also known as ammunition brass, it is composed of 70% copper and 30% zinc. This grade is known for its high ductility, excellent cold working properties, and good corrosion resistance. These properties make C260 ideal for forming and bending processes, and it is often used in applications such as ammunition casings, automotive radiators, and general purpose parts that require a combination of formability and strength.
C360
Free-cutting brass contains 61.5% copper, 35.5% zinc, and 3% lead. It is known for its excellent machinability, which is enhanced by the addition of lead, allowing for high-speed machining without significantly compromising the alloy’s strength or corrosion resistance. This makes C360 a top choice for precision parts, fittings, fasteners, and screws.
C385
Commonly known as architectural bronze, it is composed of 57% copper, 40% zinc, and 3% lead. This grade combines good machinability with corrosion resistance, is easy to forge, and is well suited for decorative applications. It is often used for architectural hardware, door handles, and decorative accessories where both aesthetics and durability are important.
C464
Known as Admiralty Brass, it is composed of 60% copper, 39% zinc, and 1% tin. The addition of tin gives C464 excellent corrosion resistance in saltwater environments, as well as good strength and wear resistance. These properties make it suitable for marine applications such as marine hardware, propeller shafts, and other parts exposed to harsh marine conditions.
C230
Red brass, with a composition of 85% copper and 15% zinc, is known for its rich color and high corrosion resistance. It is softer and more ductile than other brass grades, making it easy to form and polish. This grade is often used for plumbing, electrical applications, and decorative hardware, especially where aesthetics are important.
In summary, choosing the right brass grade depends on the specific requirements of the application, such as machinability, corrosion resistance, and formability. By understanding the properties and best uses of each grade, one can make an informed decision, ensuring the selected material meets the performance needs of the project.
What are the advantages of Brass CNC Machining?
Brass offers helpful properties that make it a perfect option for several applications. Below are some of the benefits of brass when it comes to CNC machining.
1. The material is easy to be machined – brass is among the easiest materials to machine. Even though some may prefer free-machining steels, brass alloys have better machinability than any other.
2. Its strength and hardness – due to hardness and the strength of the brass, it can be used in a wide range of applications. Moreover, it is softer than other elements such as steel alloy. However, it is weaker than most of them.
3. Better machinability – another advantage of brass is its machinability. It is commonly used in CNC machining over other materials due to its machinability. For uses that do not need the hardness and strength of steel, brass is the best option.
4. It is corrosion resistant – apart from showing the same favorable hardness and strength you would get from aluminum alloys, brass is corrosion resistant. It is even more remarkable when alloyed with some amounts of aluminum.
5. Very attractive – the other benefit of brass CNC machining is how visually appealing it is. Compared to other materials, brass does not need any extra coating.
Finishes and Post-Processing Options
Just like copper and steel, brass is not coated. This is because of its corrosion resistance, in-built conductivity, and low friction among many other benefits.
Nevertheless, some prefer a clear coating if it is exposed to some elements or the application is cosmetic. Below are a few helpful finishes and post-processing options for CNC machined brass.
Just as it is machined
One benefit of brass is that it easily accepts machining. Hence, the freshly machined surfaces normally come out looking attractive and pretty. This means you may not need any additional finishes.
Thus, it is possible to leave some parts just as they were machined. However, the surface finish can be enhanced with extra finishing passes.
Hand polishing, honing, and buffing
Brass is an attractive material used for several practices. But in most cases, brass is chosen for ornament applications. This is because most brass alloys can show up in various colors.
For a smooth and attractive finish, hand polishing, honing, and buffing is considered. You can polish the brass to create an even and glossy surface making it perfect for aesthetic components.
Tips for Brass CNC Machining
- Working with the right tools, conditions, and equipment can enhance its efficiency.
- Using the right cutting tools will enhance the material removal and ensure mills run at a higher speed.
- Programming is also important when it comes to brass CNC machining. You need to use the right codes to set it based on your needs.
Is brass hard to mill?
According to experts, brass is one of the hardest materials to mill. A lot of force is needed to push the tools through the materials. In addition, it needs several types of cutting tools and may present unique problems for maintaining suitable surface finishes.
How do you cut and shape brass?
Brass is an attractive metal that works well with several materials. Fortunately, it comes in different sizes and shapes. However, if you want to use brass, you need to cut and shape it.
There are brass rods, brass tubing, and brass sheets. This means you need to learn how to cut and shape all sizes and shapes.
Cutting Brass
When cutting small brass rods and tubing, you can use a hacksaw or cutting pliers. But for larger rods, you may need to use large cutting machines.
In most cases, a handy motorized rotary can be used to cut brass tubing, rods, and sheets. Since it is not a hard metal, it is possible to cut it to the size and shape you want.
Shaping Brass
After cutting the brass, you need to bend and shape it to suit your needs. Happily, brass is also easy to bend and shape. For instance, it is possible to bend and shape brass wires with pliers.
But shaping brass sheets can be a bit difficult. Nevertheless, there are several tools you can use to make the job easier.
Brass Machined Supplier
Brass is a combination of copper and zinc. It is used in various applications because it is easy to machine, compared to aluminum and others.
When it comes to Brass CNC machining, there are various types you can use. Some of those you can use include free-machining brass, red brass, commercial bronze, and others.
However, the requirements for the final product will help determine the type of brass to use. After choosing the suitable one for your projects, select the best CNC machining.
At ECOREPRAP, we have plenty of material options for CNC machining service, If you’d like to partner with us for your next project, contact us today.
Lucas is a technical writer at ECOREPRAP. He has eight years of CNC programming and operating experience, including five-axis programming. He also spent three years in CNC engineering, quoting, design, and project management. Lucas holds an associate degree in mold design and has self-taught knowledge in materials science. He’s a lifelong learner who loves sharing his expertise.
