CNC Machining Brass 101: Here’s Everything all Machinists should Know

Brass is a metal alloy that has excellent properties that we can apply in several industrial setups. We are going to have an analyzed review of CNC-machining this versatile material and what it all entails.

What Is Brass CNC Machining

We can describe this as the process of forming intricate parts from brass by either shaping it, cutting or forming it. This process involves the use of an automated process called the computer numerical control (CNC).

The operations of CNC machining are extremely precise and highly accurate. This means you can CNC machine your brass to produce parts that are very intricate and with precise measurements.

We commonly use CNC machine brass because of some of its properties that stand out from other metals. They are easy to machine with a good electrical conductivity and a high tolerance for corrosive environments.

Benefits Of CNC-Machining Brass

When you CNC-machine your brass, you are bound to benefit immensely compared to if you opted for other metals. Let us take a swipe at some of these benefits that include:

• Precision and accuracy: since the process is automated, you can key in your parameters on your CNC machine to cut it with precision. This gives you a product that is very consistent and extremely accurate.
• Corrosion Resistance: in applications having humidity or water, brass can exhibit high resistance to corrosion. It is very durable and can give you a longer service life.
• Versatile: brass is available in various grades each having its own properties and composition. You can use these properties to machine custom make several parts for use in many industries.
• Excellent machinability: since you can easily machine it, it is easy to come up with intricate parts. These parts have very good quality and will require less machining time therefore reducing cost.
• Faster lead time: using an automated CNC machine means your processes are fast and efficient. This can greatly increase your productivity with the shortest lead times.
• Aesthetic appeal: brass has a natural golden look and with proper machining and the right finishing, you get the best visual appeal from your part. This is very important for your decorative components.

Brass Properties Suitable For CNC Machining

Brass is an alloy that is composed of a combination of zinc and copper which define its properties. You may also find additional components such as in small quantities that bring with them additional properties.

These additional components include traces of magnesium, silicon and iron. Let us have a look at the properties that enhance their ability to be CNC machined:

· Excellent Machinability

The fact that brass has a lead component makes it so easy for you to machine it. This material is known to be very ductile and highly flexible and therefore will give you an easy time when you want to CNC-machine it.

· Strong And Hard

Don’t mistake the easy machinability of brass for it being a soft material. It is actually a very strong material and has a very high durability.

· Resistance To Corrosion

This property give brass the durability it has and ensures that your CNC-machined part has a long service life. You can actually use such parts in applications having a liquid environment. Take note that the extent of this resistance heavily relies on other component beside copper and zinc such as aluminum and iron.

· Visual Appeal

If you observe closely, you will notice that your brass material has a bright golden color appearance. This natural finish does not necessarily require to give your part a surface finish once you’re done CNC-machining it.

· Malleability

The presence of copper in brass metal makes it easily malleable with the intensity exceeding that of copper. This property makes it easy for you to machine it using CNC since you can give it different shapes based on your application requirements.

Brass Grades Used In CNC Machining

We can classify brass into various grades with each having a different percentage composition of zinc and copper they contain. The properties of all these grades are based on the ratio of these components in the final brass mass.

We can analyze the grades available I detail as follows:

· Brass C220

You might people referring to this type of brass as commercial bronze but it is still a brass alloy. It a very strong and highly ductile grade that you can easily machine.

You will find it commonly used to make architectural parts or even machined to form weather strippings.

Advantages

• It displays a high resistance to corrosion
• It is highly machinable
• Very strong and ductile

Disadvantages

• You must give it an annealing finish in the event that you machined it under harsh environments

· Brass C230

It is commonly known as red brass and can withstand corrosion in addition to being moderately strong. Additionally, it can resist dezincification.

Due to its excellent anti-rust properties, you can machine it to create parts used in pipe service lines. It is also used in making rotors.

Advantages

• Can withstand dezincification
• It has a considerable tensile strength
• Highly resistance to corrosion

· Brass C360

Another name for this brass grade is the free machining brass and is actually very much used compared to the other grades. Its 3% lead content makes it highly machinable on top of having a high tensile strength.

You will find its common applications mostly in machining electrical equipment parts. Other applications include making screws and joints.

Advantages

• You can machine them easily
• Highly resistant to corrosion
• They possess great tensile strength

Choosing The Right Brass For CNC Machining

Since we have several brass grades available in the market, choosing one for your CNC machining project may prove challenging. You have to go through the properties of each grade to find out which one best fits your project requirements.

We can take a general look at some of the factors you can put into consideration:

· Machining Time

The different CNC-machining projects require different times that have a direct impact on the grade of brass that you use. If your part has requirements other than machinability, you can opt for C220 or C230 while the C360 works well for your custom brass parts.

· End User Application

All brass grades posses’ different properties and with each having its pros and cons. Each of these properties work well in different applications therefore go for the one that adapts well to yours and will last.

· Design

In as much you can easily machine brass, the design for manufacturability principles are a determinant factor when CNC machining brass. You have to come up with a simple design that does not interfere with your machining due to complexity.

CNC-Machining Brass Finishes

There are several ways you can apply finishing on your brass part after CNC machining it for either cosmetic or functionality purposes. We can look at some of the finishes that are compatible with your machined brass:

· Powder Coating

Just as the name suggests, you can coat your final brass part using dry powder that you freely pour on its surface. The purpose of this powder is to enhance your part’s resistance to corrosion and strengthen to withstand wear.

· Buffing

You can give you brass part an abrasive surface polish to remove any impurities and give it an aesthetic shiny look. You can use an abrasive disc on a wheel to effectively achieve this.

· Electroplating

You can dip you brass part inside an electrolyte to coat it with other metal molecules. You can electroplate with metals such as aluminum to give it a very glossy finish.

Applications Of CNC-Machining Brass

The applications of CNC-machined brass parts cuts across very many industries. Let us have a look at the most common ones that heavily rely on CNC machining brass in their applications:

· Automotive Industry

An example of the very many components you can find in this industry include sensors, radiators and very many others. They are preferred because we can easily machine them and the parts produced are durable.

· Aerospace Industry

Since CNC-machine brass is very accurate and precise, it us used to form precision components used in this industry. Such components include fasteners and connectors that have a longer service life and very reliable.

· Electrical Applications

With its good electrical conductivity and resistance corrosion, it is the best material for electrical terminals connectors and other components. We can also use it to give electronic components a visual appeal.

· Architectural Decorative Parts

Its natural gold appearance coupled with a good surface finish can give your architectural fittings a good visual appeal. Such fittings include door handles, window grills and other ornamental elements.

CNC-Machining Brass Tips

You can carry out some of the following practices if want the best results from CNC-machining brass:

• Go for a brass grade matching your application requirements
• Use the correct heat management techniques to prevent overheating during machining
• Use the correct tools operating at the right speeds to reduce tool wear

Conclusion

Now that you have a clear understanding of the different brass grades, you can use their properties to optimize your machining. Your part can also have the perfect finishing from the ones that we have discussed above.

More resources:

CNC Machine Tools – Source: TSINFA

All About Brass – Source: XOMETRY

CNC Machine Types – Source: TSINFA

G-code for CNC – Source: TSINFA