Brass is a metal commonly used in various industries due to its many desirable properties. The alloy contains copper, zinc and other metals such as magnesium, iron and lead. All of these metals contribute to its properties and the lead content makes them very viable. For this reason, the metal is suitable for CNC machining of brass.
In this brass CNC machining guide, we explore the properties of brass and the different types of brass used for custom brass parts. We will also explore brass manufacturing applications and factors to consider when selecting brass for a machining project.
What properties make brass suitable for CNC machining?
As already mentioned, brass mainly contains copper and zinc. It may also contain other metals such as silicon, iron, lead or magnesium, which give it additional properties. The thing about brass, however, is that the copper and zinc content can be adjusted to suit any intended application. These different proportions of brass are what create the different types of brass used in machining custom brass parts.
Let's look at these properties and their influence on the suitability of brass for the CNC machining process:
1. Easily editable
Brass is one of the easiest metals to work with. This property is due to the lead content in its composition. With machining characteristics such as high feed rates, good ductility and flexibility, machining brass is an easy task for most machinists. The machinability of brass is the main reason why CNC brass manufacturing is widely used.
2. Corrosion resistance
One of the properties that make brass a suitable choice for machining is its resistance to corrosion. This property is one of the reasons why brass tools have a long service life. Furthermore, parts made from this material are suitable for use in liquid environments. However, the degree of corrosion resistance depends on the number of components, such as iron and aluminum.
3. Malleability
Brass is extremely malleable due to its copper content. However, the metal is even more malleable than copper. Its high malleability makes it an easy choice for machining projects. This is because machinists can easily shape the metal into different shapes. For this reason, custom brass parts are machined.
4. Strength and hardness
Despite its ease of machining, brass is also known for its strength. Although it is not as strong as steel, it is also quite durable.
5. Aesthetic appeal
One of the most important factors in machining is the aesthetics of the finished part. With its shiny golden color, brass definitely has an appearance to match its other features. Due to their beautiful natural finish, machined brass parts can be used without external finishes.
Brass grades for CNC machining
There are different types of brass, all depending on the copper and zinc components it contains. These differences in composition also affect the application properties of different types of brass. This section explains some of them along with their advantages, disadvantages and applications.
1. Brass C360
Machinists often refer to this alloy as free-cutting brass. It is the most commonly used type of brass in machining. It is known for its high machinability and tensile strength. Its high machinability is due to the lead content, which represents around 3% of its components. Machinists use it to machine special brass parts, such as electrical devices and fittings or screws.
Benefits
- Easily machined.
- Corrosion resistance.
- Good tensile strength.
Disadvantages
- Lead content can cause problems when used for medical purposes.
- Susceptible to acids.
2. Brass C230
Machinists refer to this type as Nordic bronze or brass. It also has moderate strength and good anti-rust properties. C230 is popular due to its resistance to seasonal cracking and dezincification. Manufacturers also use it to make plumbing because of its resistance to water corrosion. It is also suitable for customized parts such as rotor rods, J-tube elbows, etc.
Benefits
- Resistance to dezincification.
- Moderate tensile strength.
- Corrosion resistance.
Disadvantages
- In aggressive environments, it may not resist corrosion.
3. Brass C220
Machinists refer to this alloy as commercial bronze. Despite the name, it is still a brass alloy due to its higher copper content. It has good machinability, strength and ductility. It is popular in the architectural world and is used to process caulking.
Benefits
- Excellent corrosion resistance.
- Good machinability.
- Good ductility and strength.
Disadvantages
- Additional annealing treatment may be required after exposure to aggressive environments.
Finishing Options for CNC Machined Brass
Brass does not have its own natural coating. However, because of its natural gold finish, you can use a machined brass piece just as it is machined. If the piece has cosmetic use, you may want to give it an exterior finish. Some compatible finishing options for CNC machining of brass are explained below:
1. As edited
Because brass has a naturally aesthetic finish, some prefer to use machined brass pieces. In most cases where this finish is used, the focus is usually on the functionality of the piece rather than aesthetics. However, these parts can be easily damaged.
2. Polishing
The surface of the customer-specific brass part is polished with a grinding wheel and grinding wheel. The abrasives in the disc help remove impurities and smooth the surface.
3. Electroplating
This finishing option involves attaching molecules of another metal to the surface of the brass piece using an electrolyte. Examples of metals used are aluminum, stainless steel, etc. Electroplating generally creates a shiny or smooth surface.
4. Sharpening
This finishing process involves using sharpening stones on the surface of the finished piece. This creates a crosshatch pattern on the surface of the brass piece.
5. Powder Coating
This surface treatment involves coating the surface of custom brass parts with free-flowing dry powder. Powder coating improves the corrosion and wear resistance of brass metal.
Factors to Consider When Choosing Brass for CNC Machining
Choosing brass for a CNC machining project can be a little more difficult than it seems. Since there are different types of metal, you need to consider which properties of these types are suitable for your project. Therefore, it would be helpful if you made a list of factors to consider before choosing a specific variety. Below we list some factors that you can work with:
Processing time required for the part
Lead times for different projects vary, which is an important factor in determining what type of brass to use. In CNC machining of brass, C360 alloy is the best option in terms of machinability. So if you are in dire need of a custom brass piece, C360 is a big favorite among the materials. However, if you require properties other than machinability, you may consider other grades such as C230 or C220.
Design for manufacturability
DfM principles are essential to any editing process. Although brass grades are fairly easy to machine, you need to ensure that your part design is not too complex to machine. It is also advisable to minimize the number of machine settings required. This helps reduce project processing costs.
Application of the finished part
The different compositions of brass types mean they all have different strengths and weaknesses. This means that the location of the part will impact which brass is suitable for the machining project. For example, if the part is intended for underground pipelines, it is better to use grade C230.
Brass Machining Parts Applications
Applications of the brass CNC machining process include the production of parts such as:
- Hinges
- Buttons
- Sanitary facilities
- Bells
- Jewel
- streaming
- door panels and so on.
How do you know if brass is the right choice for your CNC project?
CNC metal machining uses various metals as raw materials for machining. If you choose brass as the right metal for your CNC project, you will need to ensure that your machined part applications match the property profile of your brass type. For example, the use of C220 grade brass for subsea piping is not advisable.
Create machined brass parts with WayKen
Our experts have extensive knowledge of the brass CNC machining process. We offer various CNC machining services such as milling, turning, drilling, EDM, etc. Furthermore, our production processes are certified by ISO 9001 and you can always count on the best machined parts.
You can contact us to request a quote for any brass manufacturing process. One of our project managers will review your request and obtain a quote and DFM feedback for you within 12 business hours.
Common questions
What is the tolerance range for brass?
The tolerance range for brass can be up to 0.005 mm.
Are there any disadvantages to CNC machining brass?
Although there are no apparent disadvantages to the machining process, some types of brass have several individual disadvantages. One example is the acid sensitivity of C360.
How long does it take to process brass?
The lead time for CNC brass part is generally less than 5 days. However, it also depends on the number and complexity of the parts.
