The Common Uses of Bronze

For two thousand years, bronze represented the ultimate in material science for ancient humanity. The Sumerians in Mesopotamia (modern-day Iraq) were the first to perfect making bronze, about 5500 years ago. This new material was the hardest readily available metal, and both the knowledge of how to make bronze and tools, fixings, weapons, artworks and jewellery made from it spread out across the Old World. Bronze opened up new possibilities for human creativity and inventiveness. The predominance of bronze gave this era of human civilisation its name – the Bronze Age.

About 2300 years ago, bronze was replaced by iron as the material of choice for tools and weapons. But bronze has by no means gone away. Its unique properties and appearance mean that it has been used for millennia since the Bronze Age and continues to be an essential material in many modern applications, industries and artworks.

A Versatile Metal Alloy

Before answering the question “what is bronze used for?”, we need to understand what it is – it’s not a naturally occurring material. Bronze is an alloy, consisting mostly of copper with around 12 per cent of tin. Small amounts of other elements – metals and non-metals – can be added to give varieties of bronze specific properties.

Bronze’s main advantage is that it is much harder and stronger than pure copper while retaining many of that metal’s desirable features, such as its low melting point, ductility, low friction, good electrical conductivity and corrosion resistance. This makes bronze a durable material that can still be readily worked into intricate and precise designs.

Industrial Applications

Although surpassed in many areas by iron, steel and other metals, bronze is still unmatched in certain industrial uses. Bronze’s wear and corrosion resistance, and its inherent low friction make it ideal for bearings, bushings and gears, so long as the overall strength required is relatively low (otherwise modern engineering steels are superior). Bronzes with higher lead content are known as ‘self-lubricating’ because they produce so little friction. Other forms of bronze have a porous structure which retain lubricants for long periods.

Bronze is especially useful in marine environments where metal fittings and components need to be strong, precise and corrosion resistant. Bronze is a traditional – and still widely used – material for ship propellers, since it can be cast to the precise and complex curved shapes required. Bronze with a small amount of phosphorous (phosphor bronze) is used for components in pumps and valves which must remain fully functional when handling water, when submerged in it or when placed in harsh environments.

Electrical and Plumbing Systems

This combination of precision, durability and corrosion resistance also makes bronze the best choice in certain plumbing fixtures and other water fittings. While copper and brass may be more cost-effective in many cases, bronze is best when reliability and durability are key. This is especially the case for parts such as valves, stopcocks and taps that may not be moved for long periods of time but have to work reliably when they are. A kitchen tap that’s used multiple times per day can be made of brass, but you’ll likely find that the main water valve under the sink or in the cupboard under the stairs, which may sit for years between uses, is made of bronze to ensure it doesn’t corrode. Safety-critical valves like fire hydrants will also often feature bronze parts.

Bronze can also be used in electrical components because of its corrosion resistance, ductility and good conductivity. When work-hardened, phosphor bronze has ideal properties for springs, making it suitable for electrical switches and connectors that must retain reliable contact and constant pressure, especially in tough environments where copper or brass would corrode.

Away from the functional electrical parts, bronze is also a common material for making light fittings. This is because it can be cast into intricate but precise shapes while possessing good strength. Louis Tiffany popularised the use of bronze for the body of table lamps, using the alloy’s rich, dark tone to contrast with his lamp’s famous bright stained-glass shades.

Art and Sculpture

Those qualities of bronze were attracting artists centuries before Tiffany. From the Bronze Age to the present day, one of the most consistent uses of bronze metal alloy is for artwork and sculptures. From the 4000-year-old ‘Dancing Girl’ sculpture of the Indus Valley and the bronze statues of ancient Greece to the intricate heads of the Benin Bronzes and the Victorian statues found in cities throughout the world, bronze is a favoured choice for sculptures. To the extent that such sculptures are often simply called ‘bronzes’.

This is because it is strong and durable, while also being able to be worked and cast to capture fine details. It has an attractive appearance when new or polished and develops a unique and pleasant patina when weathered.

Coins and Medals

Another traditional use of bronze has been for minting coins and medals. This is because these items are, in effect, miniature sculptures, so bronze’s precision, durability and attractive appearance all make it a good choice. In this context, bronze is perhaps best known as the material of the medals given to the third-place finisher in contests of the Olympic Games. That tradition has spread to other contests. In fact, bronze was – and still is – the most common metal used for high-quality medals of all sorts.

Roman coins were made from bronze, and it remained a common choice for coins of lesser value for centuries (as with medals, silver and gold were favoured for items of higher value). British 1p and 2p coins were made of zinc-rich bronze until 1992 when they changed to copper-plated steel (which is why they do not go the same dark black/brown colour with age). This was because of the increasing volume of coins that needed to be made and the rising cost of the necessary materials.

Musical Instruments

A lesser-known area where bronze excels is in the manufacture of musical instruments. While it doesn’t lend its name to a family of instruments in the way that brass or wood does, bronze is widely used for percussion instruments such as cymbals and bells, due to its excellent acoustic properties. Because it responds so well to casting, bronze is ideal for making consistent shapes that will resonate with the desired sound and tone. It’s also a strong material that can withstand the impacts required of percussion instruments. Bells, especially in churches, cathedrals, temples and other places of worship but also in secular buildings such as schools, universities and city halls, are a particularly important use of bronze. The largest bronze bell in the world is the Bell of Good Luck, installed in a temple in Henan, China. It weighs 116 tons and is 8 metres tall. By contrast the famous Great Bell in the clock tower of the Palace of Westminster in London (otherwise known as Big Ben) is 2.3m tall and weighs 13.5 tons.

Conclusion

From the halls of art museums to the decks of ships, and from around the neck of an Olympic athlete to the cupboard under your sink, the uses of bronze are as diverse as this metal’s history is long. And today, whether you need bronze for industrial or artistic purposes, Rapid Metals can help. We’re one of the UK’s leading stockists of bronze, able to supply quantities large or small of phosphor bronze rounds and bronze tube. Contact us to discuss your needs and find out more about our services.