For many people, knowing the difference between brass vs copper can be a difficult task. Even more difficult is knowing whether to use brass or copper for your next big machining project. Although brass vs. copper are similar, you must understand the key differences between them as their performances vary for different applications.
But, how do you know brass from copper? When do you choose brass or copper for your task at hand?
This blog post compares brass vs. copper, their strengths, and their performances. With this guide, you’d decide better about which of the two is the better option for your project.
What Is Brass?
Brass is an alloy of copper and zinc.
While copper gives brass its conductivity, the zinc in brass increases its strength, elasticity, and hardness. So, as the quantity of zinc increases in the brass metal, you should expect the brass to become more flexible.
In addition to the elasticity and strength, zinc gives brass a yellowish hue. When you see brass that has a bright yellow color, the quantity of zinc in it is higher. Brass with a darker color that looks more like red or brown has more copper than zinc in it.
Sometimes, other elements like Lead, Tin, or Iron may be added in small quantities to brass. Usually, adding other metals to the brass is only necessary when you want to improve specific qualities of common brass to achieve a special purpose. Any brass with more metallic additives other than the primary components is called special brass.
Composition of Brass
As you earlier read, brass is formed by combining the metals—Copper (55–95%) and Zinc (5–45%). Since there’s no rigid formula to the combination, you can have different types of brass with different percentages of Copper and Zinc. Currently, there are about 100 types of this alloy.
Special brass is a kind of brass that has other additives to improve its quality. Common additives include Lead, Tin, Manganese, Iron, Nickel, and so on.
Properties of Brass
- Brass has a shiny yellowish-gold color
- Harder than pure copper
- Resistant to corrosion especially in saltwater
- Poor conductor of electricity compared to copper
Pros of Brass
- Attractive appearance, so it’s great for decorative use
- Durable and corrosion-resistant
- Relatively cheaper than pure copper
- It’s easy to machine and shape
Cons of Brass
- Lower electrical and thermal conductivity
- Prone to degrading easily
- Brass looks like gold, so people mix them up often
What Is Copper?
Copper is a natural metal that looks reddish-brown or reddish-orange. Copper had been existing for years, as it was one of the first metals used to develop crude weapons thousands of years back. In addition, it is malleable and easy to machine too.
Copper is great at conducting heat and electricity, so it’s the gold standard metal for the conductivity of metals. It’s used in electrical systems, plumbing, roofing, artistry, etc.
Composition of Copper
Copper has about 99.9% of the pure copper metal. And, for commercial purposes that need pure copper, it’s used that way without alterations.
Nevertheless, this copper may contain some impurities like oxygen, silver, or sulfur in really minute amounts.
Properties of Copper
- Copper has a reddish-to-orange or brown color
- High electrical and heat conductivity
- Resistant to corrosion
- It resists bacterial growth too
Pros of Copper
- Excellent electrical and heat conductivity
- Excellent resistance to corrosion
- Easy to recycle and reuse
- It hinders the growth of microbes, so it’s ideal for health-related applications
Cons of Copper
- It’s prone to dents and wear with time as it’s soft
- Pure copper is more expensive than brass
- Tarnishes and gets dull over time
Key Differences Between Brass vs. Copper
Although both look similar and contain a high composition of copper, both metals are very different. The major differences between brass and copper are explained below.
Density
The density of brass varies, and it depends on the amount of other metals added to the brass to improve its quality. Most often, brass has a density between 8.4 and 8.8g/cm³.
On the other hand, copper is only slightly denser than brass as it has a density of 8.96g/cm³.
Color
Brass, depending on the amount of zinc in it, has a yellowish color. The more the quantity of zinc in the mix, the brighter the yellow. This yellow color can be deceptive, though, as some kinds of brass can be mistaken for gold.
Copper is more reddish or orangish-brown.
Content
Copper only contains pure copper at around 99.9%, but you can find minute impurities in the form of other elements. Brass is produced by combining zinc and copper majorly, so brass contains around 40-90% copper. However, some brass have other metallic additives to boost certain qualities.
Magnetism
The atomic structures of copper and zinc make them non-magnetic, so ideally, copper and simple brass should not attract a magnet. However, these days, magnetic metals are added to make brass, so some types of brass can attract a magnet.
Melting Point
Since the content of copper is static, its melting point is estimated and fixed to be 1083 ℃. You can’t say the same for brass though. Brass is a mix of two or more metals, so depending on its content, the brass metal melting point is around 1035⁰C to 1085⁰C.
Sound
Because copper is the softer metal out of both, it has a quieter sound when you strike it with another metal. Brass, in contrast, gives a shrill high-pitched sharp sound when you strike it.
Plasticity
The plasticity of an object refers to the ease at which you can shape or deform that object. Copper is the softer metal out of the duo, so at room temperature, it is more malleable and it has a great plasticity. This makes working with copper way easier.
On the other hand, brass has good plasticity due to its copper content, but it’s not as malleable as copper because of the zinc in it.
Ability to Resist Corrosion
Because of its atomic arrangement, copper is more likely to corrode as upon reaction with oxygen, it forms copper oxide. Although this corrosion happens soon, the reaction forms a patina over the copper object. This patina is what keeps copper safe over time.
Brass, especially those with iron, is more likely to rust. However, it’s more resistant to corrosion.
Conductivity
Copper is the gold standard metal when it comes to conducting heat or electricity. Unadulterated Copper has a conductivity of 100%.
Since brass is adulterated, it has a lower heat and electrical conductivity that can be as low as 28%.
Durability
Copper is way easier to reshape and machine as it’s malleable. So it’s best for metallic parts that do not need strength as it’s not a durable metal. Brass is more rigid, and it has the penchant to last longer due to other metallic additives.
Tensile Strength
Pure copper has a tensile strength of approximately 39,000 psi. The tensile strength of brass is not fixed as the amount of copper and zinc used to make brass is not certain. Depending on the amount of zinc and other metals in the brass, its tensile strength is between 35,000 and 60,000 psi.
Application of Brass Vs. Copper
Copper is used for making several equipment and in many industries. It’s used in the electrical industry to make conducting wires, cables, switches, transformers, and so on. It’s also used in the medical industry, waveguide industry, for connecting computers, for making bus bars, etc.
Brass is heavier, so it’s used in places where you need malleability, strength, and rigidity. You can use brass for ships, cars, heavy-duty machine parts, electric power, and for applications that need metals that are less resistant to corrosion.
These fields include plumbing fittings, jewelry, shell casings, water tanks, musical instruments, decorative objects, and so on.
Ways to Tell Brass From Copper
In those times when copper and brass look so similar, these hacks will help you differentiate them.
Color
Sometimes, you may have two colored metal blocks and you are unsure about how to tell copper from brass. To differentiate them with ease, keep in mind that unpainted copper has a reddish hue, while brass is more yellow or gold.
Weight
Copper may seem light because it’s malleable and easy to machine. But when compared with brass of the same size, copper is heavier.
Sound Test
The sound test is one of the most proven ways to accurately differentiate brass from copper. When you tap both metals with another metal, copper gives off a dull and lower tune in return. Brass, on the other hand, gives a sharp soprano-like sound.
Magnet Test
Ideally, neither brass nor copper should be magnetic. Sometimes, brass can respond to a magnet a bit if it contains a little iron. The magnet test can differentiate brass and copper from painted iron or stainless steel, though.
Developing Patina
Copper is more likely to oxidize, and the oxidation of copper yields a greenish color on the surface of copper. This greenish look is known as a patina. Nevertheless, brass doesn’t get the greenish coat, but it can tarnish and fade with time.
Scratch Test
Use a sharp metal to scratch a hidden spot of the sample you can’t differentiate. Brass is more difficult to scratch.
When to Choose Brass or Copper
Even if brass and copper have similar compositions, some situations will need you to choose one over the other.
You should choose Brass if:
- You need a long-lasting, shiny, or decorative material for whatever purpose.
- You don’t have enough money.
- You want a metal that’s easy to work with, yet you can customize it for heavy machines.
You should choose Copper if:
- You need an excellent electrical or heat conductor.
- You need a material that’s safe for water systems.
- It doesn’t remove corrosive particles after a while.
Conclusion
Although brass vs. copper share certain similarities, both are different, and they have their unique applications. Brass has a shiny appearance and it lasts long, so it works greatly for decorative and industrial use. On the other hand, copper is a good conductor of heat and electricity, and its strengths make it a top choice for electrical, plumbing, and health applications.
When you fully understand the differences between both, you’ll make smart, better, and cost-effective decisions.
FAQs
Can Copper and Brass Be Recycled?
Yes, you can recycle brass and copper without degrading their quality.
Do Copper and Brass Degrade Over Time at the Same Rate?
No, copper and brass do not degrade at the same rate. Copper looks like it degrades first as it forms a greenish covering over it. This greenish surface coat is called patina, and it protects the copper from degrading any further.
Brass is more resistant to corrosion as it takes more time to change its color.
Can I Substitute Brass for Copper or Vice Versa?
Sometimes, you can do that, but it depends on what you want to do. If you want to decorate, you can substitute copper for brass. But when you want electrical and thermal applications, copper has better conductivity, so it’s better to use copper when you have both options on site.
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