Although both brass and bronze are copper alloys, they differ in composition, mechanical properties, machinability, and product performance. This article will explain the differences and guide you in choosing the right one, which will be helpful for your CNC machining projects, including CNC machined brass parts, bronze components, and other custom copper alloy applications.
What Is Bronze
Definition of Bronze
Bronze is a group of copper alloys primarily composed of copper (Cu) with tin (Sn), aluminum (Al), silicon (Si), beryllium (Be), or other alloying elements added to improve specific properties.
Types of Bronze
Depending on the added elements, bronze can be divided into many types. The following are the main types of bronze for your reference.
| Type | Composition | Properties | CNC Consideration |
| Tin Bronze | 3-14% Sn | Wear resistance, good elasticity | Good machinability |
| Aluminum Bronze | 5-12% Al | High strength, corrosion resistance | Requires proper tooling |
| Beryllium Bronze | 1.6-2.0% Be | High elasticity, fatigue resistance, and moderate electrical conductivity | Specialized machining |
For CNC machined bronze parts, common choices include C932 bearing bronze for wear-resistant components and C954 aluminum bronze for high-strength industrial applications.
What Is Brass
Definition of Brass
Brass is a copper alloy with zinc as the main alloying element and copper as the base material. The content of zinc significantly affects the various properties of brass. Increasing zinc content generally increases the strength and hardness of brass while reducing its ductility and formability.
Types of Brass
| Brass Grade | Zinc Content | Color | Machining / Processing |
| C210 (Gilding Metal) | Approx. 5% Zn | Closest to pure copper color (reddish yellow) | Easy to stamp, draw, bend, weld, and electroplate |
| C260 (Cartridge Brass) | Approx. 30% Zn | Bright golden yellow | Best for stamping, deep drawing, and forming processes and also suitable for CNC machining |
| C280 (Muntz Brass) | Approx. 40% Zn | Lighter yellow than C260 | Ideal for extrusion, forging, and hot working processes |
| C360 (Free Machining Brass) | Approx. 35% Zn + 3% Pb | Yellow | One of the most common brass grades for CNC machining, and it is ideal for turning and milling. |
| C464 (Naval Brass) | Approx. 40% Zn + 1% Sn | Reddish gold | Suitable for various welding methods, commonly used for CNC boat parts, valves, and pumps |
Due to its excellent machinability, C360 brass is one of the most popular materials for custom CNC brass machining parts, including connectors, fittings, fasteners, and precision components.
Bronze vs Brass: Advantages and Disadvantages
Many design drawings often confuse brass and bronze. Similar copper alloys can cause on-site faults such as wear and jamming, zinc loss corrosion, and insufficient bearing capacity if used incorrectly. Here are the advantages and disadvantages of these two types of materials to help you quickly determine the material solution suitable for the specific application conditions.
Advantages & Disadvantages of Bronze
Advantages
- Excellent wear resistance
Bronze has high hardness and wear resistance. When your parts need to undergo long-term movement or withstand friction, choosing bronze can reduce the risk of wear failure and extend the service life.
- Excellent corrosion resistance
Bronze exhibits excellent corrosion resistance in humid, seawater, and chemical environments.
- High strength and load-bearing capacity
Bronze typically has high mechanical strength and can withstand significant pressure and impact. This enables your design to be smaller and more compact while still bearing higher mechanical loads.
- Excellent shock absorption performance
Bronze has good vibration-absorbing properties, which can reduce noise and vibration during mechanical operation.
- Good dimensional stability
Bronze maintains good dimensional stability during temperature changes and long-term use, making it suitable for precision mechanical applications.
Disadvantages
- High processing difficulty
When processing bronze materials, due to the rapid wear of the tools, the processing time will be longer. This is also an important factor that you need to consider when determining the delivery time and cost. Therefore, you need to better balance the material performance and manufacturing cost.
- Low ductility
If your design is overly complex and the wall thickness is thin, then bronze cannot fully meet your design requirements. If you must choose bronze, then you must avoid overly complex geometric structures.
- Low electrical conductivity
Although bronze has a certain electrical conductivity, due to the addition of elements such as tin and aluminum, its electrical conductivity is lower than that of pure copper and some types of brass.
Advantages & Disadvantages of Brass
Advantages
- Excellent processing performance
Brass is a very commonly used material in CNC machining, especially C360.
- Good plasticity and forming performance
Brass has excellent ductility, which makes it convenient for you to manufacture complex-shaped parts and a wider range of products. Besides, it can be processed by CNC manufacturing as well as through stamping, stretching, bending, and extrusion.
- Excellent surface effect
After processing, brass can easily achieve a smooth and attractive surface. You can choose polishing, electroplating, sandblasting, nickel plating, etc. according to your product requirements. Of course, without surface treatment, brass is very prone to oxidation.
Disadvantages
- Limited Wear Resistance
The hardness and wear resistance of brass are lower than those of some types of bronze. If your parts are exposed to a wear-prone environment for a long time, their service life may decrease.
- Lower Strength
The strength of ordinary brass is usually lower than that of some high-strength copper alloys. Brass is more suitable for: precision parts, connectors, and some decorative components.
- Limited Marine Corrosion Resistance
Some brass may undergo dezincification in marine environments. This can result in a decrease in the strength of your product and a reduction in its service life.
- Poor High-temperature Performance
In a high-temperature environment, the strength of brass decreases, its hardness reduces, and it may undergo deformation. When designing parts for high-temperature use, you need to consider the working temperature range of the material as well as its long-term stability.
Differences Between Bronze vs Brass
Apart from the advantages and disadvantages of bronze and brass, there are many other differences between them.
Appearance
The appearance of bronze mainly shows dark red, brownish yellow, and deep gold colors, while brass usually presents a bright yellow color.
Weight
The density of bronze is usually higher, with a weight of approximately 8.7–8.9 g/cm³, while the density of brass is about 8.4–8.7 g/cm³. Therefore, with the same volume, the weight of brass is slightly lower than that of some types of bronze.
Hardness
Bronze generally has higher hardness than brass, making it more suitable for wear-resistant and load-bearing applications.
Machinability and Machining Cost
Due to the high hardness of bronze, the cutting tools wear out faster during CNC processing, resulting in a slower processing speed. Therefore, the CNC machining time is longer, leading to generally higher processing costs for bronze. When designing products, you need to fully understand this point.
However, the CNC machining cost of brass is lower because it is conducive to cutting and the surface quality is easier to control.
So, overall, the machining cost of brass is lower than that of bronze.
Applications
Considering the physical properties of bronze, it is mainly used in bearings, bushings, gears, marine components, valves, and pumps.
While brass is more suitable for high-precision processing, complex structural design, and mass production. Brass is widely used in electrical connectors, precision CNC parts, screws and fasteners, fittings, and decorative components.
How to Choose Between Bronze and Brass
When your parts involve continuous relative sliding, heavy load-bearing, or long-term exposure to corrosive environments, bronze should be preferred due to its outstanding wear resistance, load-bearing capacity, and corrosion resistance, thereby extending the service life of the components.
If your project aims for high processing efficiency and surface decoration effect, while also requiring control of the overall production cost, precision components should be selected from brass, taking advantage of its superior machinability.
FAQ
Is bronze copper?
Bronze is not pure copper. It is a copper alloy made by combining copper with other elements, traditionally tin.
Is brass copper?
No, brass is also a kind of copper alloy.
Are Bronze and Brass Weldable?
Both can be welded, but the welding process is more difficult than that of ordinary steel.
Brass welding is prone to zinc evaporation and pores, while bronze has a relatively better welding process window.
Are Bronze and Brass Magnetic?
Standard brass and bronze are both non-magnetic materials.
Is Bronze More Expensive Than Brass?
In most cases, the price of bronze raw materials is higher. The cost of tin and phosphorus bronze raw materials is higher than that of ordinary brass.
How Are Bronze and Brass Made?
Bronze and brass are both formed as alloys by melting copper with other elements.
Does Copper Turn Into Bronze?
No. Pure copper oxidizes naturally to form copper rust, and the natural environment cannot spontaneously generate alloy elements such as tin or aluminum.
Which Is Better, Bronze or Brass?
It is hard to say which one is better, but it depends on your requirements and applications. Bronze is generally better for wear resistance and heavy-load applications, while brass is better for CNC machining efficiency, electrical applications, and decorative parts.
How Can You Tell If It’s Bronze or Brass?
The easiest way is that from the appearance. The colors of brass and bronze are different.
Final Thoughts
Yecheng provides custom CNC machining services for brass and bronze components, including precision turned parts, milled parts, bushings, connectors, and industrial components. Our engineers can help evaluate the most suitable copper alloy based on your application requirements, machining difficulty, and production volume.
