I. Introduction
Many individuals, especially newbies in the metallurgy industry, often make the mistake of confusing both brass and bronze. Your quest to differentiate these two alloys might be an indication that you’ve also committed this mistake at some point. These alloys look similar, no doubt, particularly if you only visually inspect the two materials. In any case, just taking a visual inspection of the two alloys doesn’t tell you the whole story. And while an understanding of the differences between bronze and brass is not required to save the world, it sure might come in handy for your project. We’ll give you the full information on everything you need to know to perfectly distinguish bronze from brass. So, if you’re ready, let’s take a deep dive together.
II. Bronze and Brass: What are they?
If we must start at the beginning, then we need to define the alloys in questions – brass and bronze.
So let’s take bronze which majorly comprises tin and copper. However, other minor constituents can constitute part of the alloy in varying proportions depending on the intended use and cost. Such minor elements as zinc, nickel and lead are used in different amounts to increase properties like durability, strength, and aesthetic appeal in some cases. Nonetheless, bronze is exceptionally versatile and durable, with extensive applications spanning many years and civilizations. It can be found as the production material for things like famous sculptures and art pieces. With its distinct reddish-brown color and corrosion-resistant property, bronze is also used for marine components and in architecture where moisture is a concern.
On the other side of the coin is brass which is sometimes confused with bronze largely because it is also an alloy of copper with zinc taking up the secondary constituent position. The minor element constituting the remaining part of brass can include lead and tin in mixed proportion based on the project requirement. Due to its malleability and low melting point, brass is the preferred material in use cases such as mold designs, musical instrument manufacture, and plumbing components. Its bright golden-yellow color also makes it suitable for decorative pieces and objects.
These two alloys undergo some sophisticated procedure that starts with the extraction and smelting of copper and other constituent elements to arrive at bronze or brass. The element type and quantity depends on the project requirement like durability, formability, strength, and cost. The molten alloys are molded and cooled to get the required shapes and forms needed.
III. Bronze and Brass: the differences
Now we come to the meat of the matter: the difference between bronze and brass. And even though they appear similar, their differences are as clear as winter and summer, especially when you consider their individual properties in detail, which is the aim of this section.
A. Constituent Elements
While bronze and brass primarily contain copper, they differ in secondary composition, which often results in their strength and weaknesses in other departments. For instance, the secondary element in bronze is tin, with other minor elements like manganese, aluminum, and nickel added to improve other properties like strength, anti-rust, and hardness. For brass, the second part is zinc, with the addition of minor elements like lead and tin for its malleability and ductility, which makes it suitable as a forging material for different complex shapes. However, the amount of secondary and minor elements also impacts the properties of these alloys, making some bronze materials stronger than others and making certain brass materials more workable.
B. Anti-Corrosion
The ability to resist corrosion is a critical consideration in specific production environments and different projects, as these can affect the effectiveness of the final product.
While the two alloys of bronze and brass have anti-rust properties, it is confirmed that bronze offers more corrosion resistance and is more suitable in corrosion-prone environments. Additionally, the oxidation process that happens in such environments causes the creation of a copper oxide layer that prevents further corrosion of bronze materials. This is the reason bronze is often used in applications that include the production of marine equipment, vessel, and ship components as well as for outdoor elements like sculpture.
C. Thermal Conductivity
One of the critical manufacturing criteria, especially for things like a heat sink, is thermal conductivity which is the ability to pull heat away from a source and dissipate it into the environment.
Brass beats bronze to the position of best thermal conductor making it a perfect fit for manufacturing heat dissipating components like radiators and heat sinks. In contrast, bronze is less of a heat conductor than brass but what it lacks in thermal conductivity it has in heat retention. That is why bronze is suitable for devices like cooking utensils and other devices that need to retain heat.
D. Melting Point
Assessing a material’s melting point helps metallurgists and material specialists identify its suitability for use in areas and projects where resistance to high temperatures is critical. It is also used to identify materials that are easily manipulated using heating production techniques.
Bronze is more resistant to high temperatures, given its higher melting point of 950°C than brass which has 900°C as its melting point, making bronze a suitable material for engine and furnace parts. Nevertheless, brass is more workable using heating production procedures like casting than bronze.
E. Hardness
High-durable materials are often harder than less durable ones as they can better resist wear and tear in rough handling and harsh environments. Bronze is considered more durable and stronger than brass since it has more hardness value than brass. Bronze is also applicable in areas where resistance against material deformation is required, such as for engine components. Nonetheless, brass finds suitability in areas where low strength and resilience are necessary, including for musical instruments and ancillary building components.
F. Weight
One area where materials often lack manufacturing suitability is in their weight. Some applications require ease of handling and mobility which can be tedious for weighty materials. Even though the difference in density between these two is about 0.3g/cm3, bronze still has more weight than brass and can be difficult to handle where mobility of the component is the deciding criterion. However, brass has less weight and can be more suitable as a material where mobility and ease of handling top the list of requirements.
G. Durability
Due to its higher hardness, bronze is more durable than brass and suitable for applications where materials are required to withstand rough handling and harsh environments without losing their structural integrity. Heavy equipment and marine component manufacturers often prefer bronze to brass for the reasons mentioned, though brass has some level of durability.
H. Machinability
Machinability – the ability to work at a material using sophisticated and advanced machinery- is important for many manufacturers as it increases product speed, accuracy, and quality. However, the harder the material, the less machinable since you will require harder tools and more sophisticated methods to manipulate such materials. Bronze, for its high hardness value, has less machinability than brass with a lower hardness value, making it easy to use methods like CNC machining to produce complex shapes and forms with brass.
I. Formability
Both bronze and brass are easily formed into different shapes, sizes, and geometries, considering that both have copper as a primary component which is a very pliable material. However, brass has more formability than bronze with its high ductility and low melting point. Production methods like forging and molding often require high-formability materials to achieve complex shapes easily.
J. Weldability
Welding is a standard procedure for most manufacturing industries, including automotive, marine, oil, and gas sectors, where it is used to join components and parts together. The ease with which a material can be welded determines its suitability for many industries where welding is used for fabrication. Brass is generally considered a material with better weldability than bronze. However, when its zinc content exceeds 19%, its weldability reduces appreciably. Nevertheless, bronze also shows good weldability, especially if it is one without lead.
K. Yield Strength
The ability to withstand stresses without permanent deformation or failure, especially after bending, is how you measure a material’s yield strength, and it is critical for load-carrying components. And because bronze can withstand more stress without yielding, it is preferable to brass for producing devices and components subjected to extensive stresses during their working life. These components include heavy machine parts, marine vessel parts, and pipelines. Brass can still be suitable for applications requiring medium to low stress.
L. Tensile Strength
Bending forces can permanently destroy materials with low tensile strength, which is why consideration of tensile strength is critical in manufacturing components subjected to bending forces.
Bronze, due to its higher tensile strength, is often applicable in areas where the effects of bending forces are significant, such as in automotive parts and marine components. Also, brass has substantial tensile strength though lower than bronze, making it suitable for low to medium bending stress applications.
M. Shear Strength
Sometimes, loads or forces can cause materials to suddenly snap without any bending or expansion to warn of the coming danger. The ability of a material to avoid these sudden breaking is measured by its shear strength, and it is considered necessary in sectors like mold manufacturing.
Despite bronze’s high hardness value, it still is very brittle and susceptible to fractures and failures in shear. Hence, brass has more shear strength than bronze, although the difference is not much considering that brass has 35,000 to 48,000 psi and bronze has 35,000 to 47,000 psi in range.
N. Color
Where aesthetics is concerned, color criteria in material selection are vital, especially where the project specification requires a particular color finish for the product. Suitable material in strength and durability without aesthetic consideration can sometimes lead to the project’s failure.
Bronze and brass have unique colors, making them suitable for individual applications and projects. With its reddish-brown color, bronze is often used in outdoor beautifying components such as sculptures. However, this is usually suitable for use cases that require a darker finish. On the other side, brighter yellowish-colored brass is often used for indoor enhancing components and musical instrument accessories. Its lustrous surface finish is usually due to a lower copper content than bronze.
O. Price
If your budget for a specific project is below the cost requirement, this can reduce your options and sometimes even put the project to an end. Hence, considering the price of the material for your project is essential. The cost of getting bronze is higher than brass if factors like market demand and constituent elements are put into consideration. One reason is the percentage of copper in bronze, which is higher than in brass. Another reason for the high cost of bronze is its high strength and hardness, which often requires more sophisticated and advanced machining methods to work on it. However, varying the constituents of individual elements that make up both alloys can significantly affect the cost.
P. Applications
As we’ve alluded to in previous sections of this guide, bronze, and brass have unique properties that make them suitable for different applications.
Due to its high strength and hardness, bronze is often suitable for areas where high strength and durability are key requirements, especially to resist wear and tear. Bronze easily fits applications in the areas highlighted below.
- Bronze is used in producing gears in mechanical equipment and engines, as well as bushings that act as protective housings for mechanical components due to its strength.
- For moisture-prone applications, including valves and plumbing fittings, bronze most fits these applications as it has anti-corrosion properties.
- For outdoor artwork like sculptures, bronze is perfect since it is corrosion-resistant and has aesthetic appeal.
- Music instrument accessories like guitar strings, tuning pegs, and cymbals are made of bronze for their strength, durability, and weight, which produces an exceptional sound.
Where low to medium load is applied, brass is often suitable to respond adequately to the stress involved since it also has considerable strength, durability, and workability. The highlighted application below is based on brass’ properties.
- Ornamental items used for enhancing interior spaces are often made from brass, including door handles, lamp holders, and sometimes picture frames. This is due to its unique luster and color that make it appealing.
- Plumbing accessories and pipes are some of brass’ application based on its corrosion resistance and properties and high machinability.
- Musical instruments like trombones and trumpets also give unique sounds when made with brass material.
Ultimately, the final product’s project requirements and intended use will determine the material you’ll eventually pick between bronze and brass. These criteria will also inform the constituent’s quantities as these can improve a particular quality or tone down on another.
For instance, increasing the manganese quantity in bronze results in a highly corrosion-resistant and exceptionally durable material known as 863-manganese bronze, used in heavy-duty projects like bridges, cams, and gears.
Also, keeping the quantity of zinc to 5% in brass results in a characteristically soft brass known as red brass applicable in jewelry making and architectural designs requiring high formability. And mixing manganese with copper results in a high-tensile brass capable of resisting high-tensile stress often found in load-carrying components like axle boxes and locomotive wheels. There are also other types of brass, including engraving brass with 1 to 2% lead and free-cutting brass with zinc and lead that makes it strong for use in high-capacity bolts and nuts.
Other forms of bronze include aluminum bronze (955 and 954), a robust alloy used in gears, bushing, and bearings. Also, tin bronze (both 907 and 917) is used for its superb anti-corrosion properties and superior load-supporting abilities.
IV. How to differentiate between Bronze and Brass?
By this time, you are well aware of the similarities and difficulty in telling bronze and bronze apart. While we’ve been able to differentiate brass from bronze based on properties and applications, sometimes, to confirm, all of these properties can be a luxury you might not be able to afford. Instead of going through this identification route, other easy means can quickly tell you which alloy you are dealing with.
Color is usually the first point of call in identifying bronze from brass. Bronze appears darker with a reddish-brown color that is different from the radiant golden yellow of brass. Still, this method might not be the best as the compositions of these two alloys vary, which can also alter their appearance.
Sound is another valid identification criterion for these two. Hitting the brass and bronze gives two unique and distinct sounds that make them suitable for different-sounding musical instruments. For instance, hitting bronze gives a duller sound than brass which sounds brighter.
Frankly, identifying bronze from brass may be difficult, but fortunately, it is possible to tell one from the other with the simple methods highlighted above, which include color and sound.
V. Which one is best for your project?
In most projects, understanding the critical factors to consider in material selection will help you save time and cost and improve production speed, for example, in rapid prototyping. Choosing between bronze and brass follows this same logic but the question is what are the factors to consider in your material selection?
The environment where the final product will be used is of critical importance as the nature of the environment, if harsh, can adversely affect the product’s performance. Hence, the material with resistance to the effects of the environment will be best suited for the project. Therefore, bronze will be more suited for very harsh environments with high corrosion and extreme temperatures than brass.
Again, if the aesthetic is the main focus of the final product, using bronze material can result in a dull-looking matt finish. However, a glossy feel finish might require using brass for its polished surface appearance.
The project’s cost is a fundamental consideration to get your project out the door in good time. Bronze can be expensive even though its strength and durability justify its high cost. However, if you operate on a meager budget, using brass will save you much cost with fairly similar results.
The required manufacturing method is another equally important consideration, as a simple manufacturing process helps your project delivery timeline. Bronze may require a sophisticated manufacturing process because it is more challenging to maneuver than brass.
VI. Conclusion
In summary, the difference between bronze and brass is many despite both looking similar when taken at face value. However, understanding these differences requires carefully considering their properties, which serves as their basis for comparison. Yet, their applications are related to these differences, which makes one suitable for specific projects that the properties of the other do not support. For example, bronze is more robust and durable than brass, making it ideal for load-carrying applications that can cause extreme wear and tear. Yet, its brittle nature makes bronze unsuitable for projects that require significant levels of shear strength, which is brass’ forte. Ultimately, your choice will be determined by your project’s specific requirements, and your understanding of the information presented in this guide will help you make that decision. So, what are you waiting for?
