Brass and bronze all contain copper, which is why they can often be confused for each other. Although copper is an element, pure copper is not typically used to make copper parts. Instead, most copper, brass, and bronze parts are made up of a mixture of pure copper and other metals such as lead, zinc, and tin.
It’s important to understand the differences between these three materials in order to choose the best one for your parts and components. As such, this page offers a comprehensive comparison to distinguish between bronze, brass, and copper. It also presents their unique characteristics, available alloy options, and common applications.
Bronze, Brass, Copper: Their Alloys
Bronze, usually consisting mostly of copper, may also incorporate other alloy components based on its particular type. The top five frequently used bronze alloys are:
1. Phosphor Bronze
Phosphor bronze is sometimes referred to as tin bronze since it usually contains about 0.5% to 1% tin. While it only contains a small amount of phosphorus, usually between 0.01% and 0.35%, this element is vital in enhancing the durability and stiffness of the alloy. Phosphor bronze is highly useful in construction and manufacturing due to its strength, fine-grained structure, low coefficient of friction, and ability to resist fatigue.
2. Silicone Bronze
Silicone bronze is usually utilized for the coating of red bronze and red brass. It typically has about 6% silicone, and other alloys such as copper, manganese, tin, iron, and zinc may also be included. This high-strength alloy possesses good pouring ability, excellent corrosion resistance, and an attractive appearance. It is widely applied in pump and valve parts.
3. Aluminum Bronze
Aluminum bronze is a common type of bronze alloy, which typically consists of 6% to 12% aluminum. Additional alloying elements that make up this type of bronze include up to 6% iron and 6% nickel, in addition to copper, of course. Aluminum bronze is a sturdy alloy that can resist corrosion, making it a perfect material for handling corrosive conditions such as toxic fluids and for manufacturing marine hardware.
4. Copper Nickel
Copper nickel is also known as Cupronickel. This material generally comprises 2% to 30% nickel and is renowned for its remarkable tensile strength, high resistance to corrosion and oxidation, and its ability to resist cracking even when subjected to stress. Owing to these properties, Cupronickel has become a standard material used in manufacturing marine equipment and constructing ship hulls, and it is well-suited for use in steamy or damp air environments.
5. Manganese Bronze
Manganese bronze comprises various metals including up to 3% of manganese, copper, zinc, aluminum, and iron. This alloy has excellent resistance to shock and is deformable rather than brittle. It is notably resistant to corrosion from saltwater which makes it a popular material in marine applications, particularly for boat propellers. Besides, manganese bronze is utilized in the manufacture of gears, nuts, bolts, valves, and pump components.
The versatility of brass is attributed to its elemental composition, enabling it to exist in various alloys. Among the frequently used brasses in rapid prototyping are:
- Alloy 260, also known as cartridge brass, is a highly beneficial alloy that shows outstanding cold working quality. Its versatility makes it a popular choice in various industries such as automobiles, fasteners, ammunition, and hardware.
- Alloy 272, commonly referred to as yellow brass, contains a significant amount of zinc, about 33%. This composition makes it ideal for industrial applications that require high strength.
- Alloy 330 is a brass alloy with high machinability. This alloy is particularly suitable for piping applications. It’s easy to work with and suitable for cold working because of its low lead content.
- Alloy 353, or clock brass is a highly machinable brass alloy used in creating high-precision parts like clock parts.
- Alloy 360, the most widely available type of brass, is known for its exceptional formability and machinability, making it a popular choice among designers and machinists to make hardware components, fittings, fasteners, and valves.
- Alloy 464, also called naval brass, is noted for its superior resistance to corrosion and its ability to withstand temperature changes. It’s commonly used for bending, soldering, welding, cold and hot forming processes, and more.
The versatility of copper comes with its availability in various grades. Runsom Precision provides the following copper grades for rapid prototyping:
- Alloy 101 – an oxygen-free copper. When manufacturers require high conductivity and ductility, they can employ it.
- Alloy 110 – also known as electrolytic (ETP) copper, exhibits good ductility and malleability, along with incredible electrical and thermal conductivity.
- Alloy 122 – similar to Alloy 110, it additionally possesses high formability, brazing capabilities, and weldability.
- Alloy 145 – known as tellurium copper due to its copper composition with 0.4-0.7% tellurium content, it’s available in rod & bar. It features high formability, great machinability, and good thermal and electrical conductivity.
A Complete Comparison of Bronze and Brass and Copper
Bronze vs. Brass vs. Copper: Material Properties Differences
Being a periodic table element, pure copper solely consists of copper. Nevertheless, it might have impurities or small amounts of other substances. Brass comprises copper and zinc, with minor traces of tin and other metals.
Bronze, on the other hand, is an alloy of copper and tin, along with other elements like silicon, manganese, aluminum, arsenic, and phosphorus. Despite sharing some of the same metals with brass, bronze typically contains more copper, amounting to an average of 88% in modern times.
2. Durability and Corrosion Resistance
Bronze is a rigid but inflexible metal. Copper, also a strong material, is the most malleable of the three, thus it can be easily stretched and bent without cracking or scratching. On the other hand, brass, an alloy of copper and zinc, is even stronger than copper but can be more susceptible to splitting and cracking than the other two metals.
Brass offers better protection against corrosion compared to copper, but it is still not as effective as bronze. Copper will develop a green patina with time as a result of oxidation to protect itself from further corrosion.
Choosing between bronze, brass, or copper for your project also depends on their weight. Despite having similar densities, brass is the lightest of the three, making it the ideal option if you require a lightweight metal. Bronze has a density ranging from 7400 to 8900 kg/cu.m, while copper is the heaviest with a density of 8930 kg/cu.m.
In terms of machinability, copper is superior to brass and bronze. This is because copper is a more flexible metal, which allows it to be easily bent and shaped during machining operations. Additionally, copper alloys generally have excellent ductility. In comparison, bronze is a harder and more rigid material that is more difficult to work with, while brass is also less flexible and therefore not as easy to machine as copper.
The three metals – bronze, brass, and copper – are weldable within their individual domains. They can be joined through the use of silicon bronze welding, MIG equipment, or other welding techniques. Oxygen-free copper is typically easier to weld, as well as deoxidized copper. MIG and TIG are the most commonly used techniques for welding copper.
Brass alloys can also be welded using MIG, TIG, and silver soldering. However, alloys containing lead are more challenging to weld. Welding is generally easier with alloys that have lower zinc content. Unleaded bronze has a moderate level of weldability among bronze grades. Nevertheless, they may crack when subjected to stress.
The differences in these three metals’ properties are summarized in the table below:
|Composition||Primary: Copper & Tin Others: Phosphorus, Silicon, Aluminum, Manganese, Zinc, etc.||Primary: Copper & Zinc Others: Iron, Lead, Aluminum, Silicon, Manganese, etc.||Copper|
|Weight||7400 – 8900 kg/cu.m||8720 kg/cu.m||8930 kg/cu.m|
Bronze vs. Brass vs. Copper: Conductivity Differences
1. Electrical Conductivity
Copper is commonly used as a reference in the manufacturing industry to rate the electrical conductivity of materials. Brass is about 28% as conductive as copper, while bronze has about 15% electrical conductivity, which could be due to its alloying element composition.
2. Thermal Conductivity
Among the three metals, bronze boasts the highest thermal conductivity, with a range of 229 to 1440 BTU/hr-ft²-°F. Copper comes in second place with a thermal conductivity of 223 BTU/hr-ft²-°F, while brass has the lowest thermal conductivity at 64 BTU/hr-ft²-°F.
Bronze vs. Brass vs. Copper: Their Ability to Form
Copper exhibits good formability due to its ability to undergo plastic deformation without damage, allowing manufacturers to create micron-sized wires with it. Some bronze alloys, such as PB1 phosphor bronze, also possess excellent cold-forming properties. However, brass presents more challenges in the forming process due to its relatively poor flexibility.
Bronze vs. Brass vs. Copper: Strength Differences
1. Yield Strength
Compared to brass and copper, bronze has a greater yield strength. Specifically, its yield strength ranges from 125 to 800 MPa, whereas brass possesses a yield strength of approximately 95 to 124 MPa, and copper has the lowest yield strength at 33.3 MPa.
2. Tensile Strength
When selecting a metal from bronze, brass, and copper based on strength requirements, bronze is commonly a preferred option due to its tensile strength of 350 to 635 MPa. In contrast, brass offers an ultimate tensile strength of 338 to 469 MPa, while copper falls behind with a tensile strength of 210 MPa.
Bronze vs. Brass vs. Copper: Appearance and Price Differences
Copper has a distinct reddish-brown hue, while brass appears brighter in its golden-yellow color. In contrast, bronze has a less vibrant gold or sepia tone and typically lacks prominent circles on its surface.
Different grades of bronze, brass, and copper can result in varying prices. Generally, copper is more costly than brass and bronze. The cost of bronze may be reduced by lower copper content, whereas brass is the cheapest due to a higher zinc content that is less expensive than copper.
Bronze, Brass, Copper: How to Choose the Right One
In many cases, bronze, brass, and copper, any one of these three metals may be suitable for the application. However, upon further focusing on their differences, it is often found that one offers advantages over the others.
In this part, we compare these three materials in pairs, so as to highlight the unique advantages of each one, so that you can quickly choose the most suitable material for your project.
Brass vs. Bronze
The specific purpose for which you use the component will dictate the type of metal you opt for. While both brass and bronze are copper alloys, there are distinct characteristics due to their composition, so their areas of applications are different:
If you are looking for a material to use in marine components, then bronze is a better option than brass. This is because bronze has better saltwater corrosion resistance, which makes it ideal for use in a marine environment. Moreover, it has a higher melting point, which allows it to function in high-temperature settings.
Brass is a better material than bronze in terms of workability because it is more malleable and easier to handle. Moreover, it has a brighter color, making it appropriate for decorative parts and products.
Brass vs. Copper
As brass is a type of copper alloy, it shares some characteristics with copper. Nonetheless, there are several distinctions between these two metals:
In terms of electrical and thermal conductivity, copper outperforms brass. Copper has the highest thermal conductivity of any metal, and its electrical conductivity ranks second only to silver. But, copper is vulnerable to rusting when exposed to the elements, causing a reddish or greenish tinge.
Brass is a cheaper but tougher material compared to copper. These features make it more versatile and suitable for a wider variety of applications.
Copper vs. Bronze
Bronze and copper have some similar properties, but they also have some distinct features:
Copper has a higher ability to conduct heat and electricity than bronze. This difference is even larger than the difference between copper and brass.
Unlike copper, bronze is significantly harder. This characteristic makes it more resistant to wear, but also more vulnerable to breakage due to brittleness.
Bronze, Brass, Copper: Their Applications
Various industrial applications can benefit from the use of bronze metal sheets due to their versatility and availability in different grades. Examples of such applications include:
- Propellers, ship and boat fittings
- Electrical connectors
- Electric motors
- Oil rig tools
- Petrochemical components
Brass has a similar appearance to various tints of gold and can be used for numerous purposes.
- Plumbing and piping materials
- Hose couplings
- Electrical plugs and sockets
- Electronics and electrical terminals
- Musical instruments
- Clock and watch components
- Ammunition casings
Pure copper can be utilized in the manufacturing of components and items used for plumbing, roofing, industrial purposes, and electrical appliances.
- Heat sinks and heat exchangers
- Industrial machinery
- Architectural components
- Telecommunication components
- Anti-biofuel components in submarines
- Electrical wiring
- Vacuum tubes
- Electric motors
The metals bronze, brass, and copper share similarities but each has distinct characteristics based on properties like conductivity, strength, ductility, and machinability.
Copper has a high level of flexibility and conductivity. Because of this, it is useful for parts that need to be able to flex when subjected to stress without breaking and for those needing to conduct heat or electricity effectively.
Brass is often the most well-suited metal alloy for general applications due to its malleability, low friction, ease of casting, and relative affordability.
Bronze is the hardest metal alloy among these three metals, so it’s preferred by various industrial applications. Due to their excellent corrosion resistance and durability, bronze is ideal for high-stress marine applications.
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