What is the Difference Between Copper and Brass?
The manufacturing industry handles an expansive range of metals, resulting in controversy when dealing with brass or copper. Primarily, this controversy stems from the fact that many metal users are unable to distinguish the difference in copper and brass. This is mainly due to the vaguely similar colour that each metal has when placed alongside one another. However, when properly scrutinised, there is a slight difference. Despite this, this isn’t the sole differentiation between the two metals.
What is Copper?
Copper is among the earliest discovered metals by man, and it can be utilised and worked in its natural state. During prehistoric times, decorations, weapons, and tools were crafted from this material. Copper is an element with high thermal and electrical conductivity, malleability, and softness. Whether copper is used on its own or combined with other metals to form alloys, it’s especially useful for building purposes.
What is Brass?
Brass describes a copper alloy that contains zinc, and it’s because of this that brass is regularly mistaken for copper. On top of this, brass can also contain metals such as manganese, silicon, lead, aluminium, iron, and tin. Each of these metals introduces a new characteristic to the metal. For instance, the inclusion of brass improves the strength and ductility of the copper base. Therefore, a higher zinc content results in a stronger and more pliable alloy, as well as a more yellow tinge. Since brass can often resemble gold, it’s typically used in decoration, otherwise, its workability and durability make it ideal for musical instrument production.
As previously mentioned, copper is a pure base metal, meaning it’s an element much like gold and silver. However, brass is an alloy of both copper and zinc. Depending on its alloy form, its elemental composition can vary, whereas copper’s elemental composition will always remain the same.
Regardless of the elemental composition of brass, it will never contain iron, making brass and copper alike quite resistant to rusting. Despite this, copper can oxidise over time, resulting in green patina forming on the surface. However, this prevents the surface from corroding any further. On the contrary, the variety of elements within brass make it quite resistant to corrosion, allowing brass to exhibit a gold colour throughout its lifetime.
Copper is used as the scale against which all other metals are measured in terms of electrical conductivity. Since copper displays zero electrical resistance, it’s regarded to be 100% conductive, whereas brass is only 28% conductive in comparison.
The thermal conductivity of a pure metal, such as copper, will remain the same regardless of temperature. However, when it comes to alloys like brass, the thermal conductivity will increase with temperature. For instance, copper has the highest thermal conductivity of 223 BTU, whereas brass has a conductivity of 64 BTU.
The melting point is essential to selecting any metal as this is the point at which it will transition from solid to liquid. This is likely to inhibit the metal from serving its purpose, so you need to carefully consider melting points when selecting a metal. Despite this, metals are more formable when brought to a liquid state, meaning this should be contemplated if you wish to mould your metal.
Copper has the highest melting point of 1084°C, whereas the melting point of brass will sit between 900°C and 940°C, depending on the elemental composition of the alloy.
Hardness refers to a metal’s resistance to deformation from indentation. When compared to copper, brass is much harder due to the presence of zinc within the alloy. In fact, the hardness of brass will sit between three and four, depending on how much zinc is included within the composition. On the contrary, copper’s hardness varies between 2.5 and three on the metal hardness chart.
In order to determine the weight of metals, water will be used as a baseline for gravity as a value of one. The gravity of each metal is then compared as a fraction of lighter or heavier density. As a result of this process, it can be confidently said that copper is the heaviest with a density of 8930 kg/cu.m. However, the elemental composition of brass will result in a variation of density between 8400 and 8730 kg/cu.m.
Durability refers to a metal’s ability to remain functional in the absence of consistent maintenance or repair. Each metal boasts great durability, yet copper takes the lead when it comes to flexibility.
Machinability describes a metal’s suitability to be cut whilst maintaining the surface’s appearance. Machining processes may include die-casting, cutting, milling, and much more. Brass has a much higher machinability than copper, making it the most appropriate option for projects that require formable qualities.
With this being said, copper’s formability shouldn’t be underestimated as it’s ideal for producing micron-sized wired. Despite this, copper alloys, like brass, are much stronger, meaning brass is suitable for deep drawing, stretching, bending, and coining. Ultimately, brass is extremely formable, yet copper displays an unmatched flexibility.
Although copper is more weldable than brass, all copper alloys are weldable, aside from those that contain lead. The less zinc that brass contains, the more weldable it will be. As a result, brass with less than 20% zinc is considered to have good weldability, whilst those over 20% are thought to have fair weldability. Despite this, cast brass is only slightly weldable.
Shop Copper and Brass at Rapid Metals
We hope we’ve answered your questions regarding why brass is better than copper and vice versa. You can browse our collection of copper and brass products on our online store. Otherwise, contact us with any questions and a member of our team will be in touch to offer assistance.