What Are The Different Types Of Bronze Alloys?

Bronze is one of the key materials responsible for the development of civilization, and it is still used commonly in industry today. The main difference is that it is now available in tightly controlled mixtures, known as alloys.

In this article, we’ll explain the types of bronze alloys that are available, how they are used and what makes them different.

What is Bronze?

Bronze is an ancient alloy made mostly of Copper, also containing Tin. The ratio is generally in the region of 12% Tin, a small number of other elements such as phosphorus, aluminum, manganese and the remaining percentage of Copper.

The first Bronze tools and items dated back to 3500 BC, around 2500 years before Iron was being used. Bronze was so influential that a period of human history spanning over 2,000 years was named after it.

In modern times Bronze has been surpassed by Iron, Steel and Aluminum for most purposes, but still has a few key uses, especially in its various alloyed forms, which we will explore further below.

What Type of Bronze is the Strongest?

Aluminum Bronze is an alloy containing between 6% and 11% aluminum. It is often used in marine environments for fasteners and pump shafts, as it has high corrosion resistance and strength.

Aluminum bronze alloys such as C63200 are stronger than steel, with a tensile strength of around 650 MPa.

What is the Most Common Type of Bronze Alloy?

Likely due to its high strength and corrosion resistance, the previously mentioned aluminum bronze is probably the most commonly used, it has applications in many industries and is very versatile.

For this reason, it’s the Bronze we stock in bar form in our stores, for more information and to get great prices on cut-to-size material, check out our website here.

What is the Most Wear-Resistant Bronze Alloy?

Alloy 932 is often regarded as one of the most wear-resistant Bronze Alloys. It contains high amounts of Lead and Tin. As well as being excellent for machining, it has a self-lubricating property, making it ideal for bushes and bearings.

Commonly known as Bearing Bronze, Bronze 932 is stocked in round form, perfect for making bushes, on our website.

What are the Types of Bronze Alloy?

The main alloys of industrial Bronze can be categorized into 9 segments:

1.   Tin Bronze

Containing up to 11% Tin and 89% Copper, Tin Bronzes have good strength and hardness, making them perfect for use in bushes, gears and bearings. The downside to Tin Bronze is that it is generally more expensive than other alternatives.

Tin Bronze is corrosion resistant and as such is often used in marine pumps and machinery, as bearings or bushes.

2.   Bearing Bronze (Lead Bronze)

As we discussed briefly above, Bearing Bronze is often used for its high wear resistance. This is in part thanks to its high lead content – usually around 7%. It also exhibits high strength and machinability, the latter thanks to the Lead content, which acts as an inherent chip-breaker when turning.

Applications include bearings, bushes and other rotating components in the marine and other corrosive environments. Low-friction washers used on steel hinges are often made from Bearing Bronze.

3.   Aluminum Bronze

The alloying of copper with aluminum results in excellent corrosion resistance and strength. Aluminum Bronze alloys can exceed the strength of carbon steel by a significant margin, whilst still retaining the other benefits of Bronze. Aluminum Bronze typically contains up to 14% Al and 4% Fe, with the remaining element being Copper.

Again used for bearings and bushes, but also shafts and gears in high-stress applications, Alloys such as C95900 can be used to make long-lasting marine components from.

4.   Phosphor Bronze

Containing a low but important amount of phosphorus (circa 0.2%), and up to 10% Tin, Phosphor Bronze is a hard-wearing and friction-resistant alloy. It is widely used for industrial bushes and pins, to reduce friction on moving components in both radial and linear applications.

Phosphor bronze also finds uses for springs and fasteners, its low friction nature and strength allowing efficiency in small or complex mechanisms. It can also be used in electrical contacts, where the high copper content aids conductivity.

5.   Nickel – Aluminum Bronze

As well as 4% Nickel, 9% Aluminum, and Iron is also added in small quantities to achieve a high strength and high ductility alloy. This is a useful characteristic as ductility can often be the limiting factor to materials used in critical applications such as hydraulics.

Common industrial applications include oil and gas pump components including bushes, bearings and shafts. The high ductility means catastrophic failure is not as likely with Nickel Aluminum Bronze as it is with less ductile materials.

6.   Bismuth Bronze

Often used as an alternative to Leaded bronze, the addition of Bismuth gives the free machining and high wear resistance of Lead-Bronze, without the toxicity. This makes Bismuth Bronze grades such as C89835 perfect for plumbing applications.

Whilst Bismuth Bronze is designed to be used in replacement of Leaded bronze alloys, it does not self-lubricate as well, meaning bushes and bearings should be lubricated manually to retain service life.

7.   Manganese Bronze

As well as manganese, these alloys contain high levels of zinc, aluminum and iron and achieve very good wear resistance and strength. Perfect for high-load applications, grades such as CZ114 offer over 440MPa tensile strength, higher than most low-carbon steels.

Because of their formidable strength, they are often used in aerospace and allied industries, offering wear resistance, strength and corrosion resistance in one package. Poor machinability is one downside, but weldability is generally good.

8.   Copper Nickel Bronze

Containing anywhere from 2 to 30% Nickel, there is a wide range of Copper Nickel alloys to choose from, each with slightly differing properties. One common characteristic is that they exhibit high corrosion resistance even in saltwater environments.

Applications often include sea or marine environments, including fasteners, bearing cages and shafts that are used on sea-going vessels.

9.   Silicon Bronze

Like many materials, silicon is often added to Bronze to aid in processing, specifically casting and welding performance is improved over non-silicon alloys. Around 3-5% by mass is usually silicon, with small (1%) amounts of iron and the remaining balance of copper.

With silicon-bronze machining and casting well, it finds perfect usage in manufacturing fasteners and other hardware. It is often also used in architectural applications owing to its excellent corrosion resistance.

Need Bronze? Check out your local Metals Supermarkets Store

We stock many types of bronze, including alloys perfect for bushes and structural components. Regardless of your project’s demands, we’re sure to be able to help, find your nearest store today.