Aluminium vs Steel: What’s the Difference?

Aluminium and steel are some of the most commonly used metals in the world. Titans of the construction, automotive, and aircraft industries, they are used for a virtually unlimited range of purposes. This can largely be attributed to their versatility and durability.

Aluminium is produced by refining bauxite ore to obtain aluminium oxide, and then smelting the aluminium oxide to release pure aluminium. Steel is produced by mixing iron and carbon within a furnace. Each comes in a variety of grades and forms.

Although the two share visual similarities, there are a number of key differences marking aluminium and steel as distinct. Knowing the differences is important for making sure you're choosing the right material for your project.

Clickmetal are specialists in aluminium and steel, with over 70 years' experience within the metals industry. In this guide, we cover everything you need to know about the difference between aluminium and steel, from their strength-to-weight ratios to their many possible applications.

Strength

When it comes to raw strength, steel comes out on top. Its high carbon content makes it stronger and more resilient than aluminium - it’s why it’s such a common component in the automotive industry.

Strength-to-Weight Ratio

Although aluminium is weaker, it’s also much lighter. The strength-to-weight ratios are 1/8 for aluminium and 1/16 for stainless steel, meaning that an aluminium structure that can support the same load as a steel structure will be bigger but weigh half as much.

Heat Resistance

Steel can resist high temperatures better than aluminium. Stainless steel has a melting point of around 1,400°C, while aluminium's melting point is around 660°C.

On the flipside, aluminium has the advantage over steel when it comes to the cold - as the temperature decreases, aluminium’s tensile strength increases, while steel turns brittle.

Malleability

Aluminium is much more flexible than steel, meaning it can be easily bent into various shapes. Steel is more rigid and will break if pushed too far. Aluminium is also very ductile and can be stretched without cracking.

Corrosion Resistance

Aluminium has a natural advantage when it comes to resisting corrosion. A layer of aluminium oxide protects it from exposure to air and oxygen, which are both necessary for oxidation. This means aluminium will not rust or corrode over time.

Steel has no such protection; however, some types of steel contain small amounts of alloy metals like chromium to protect against corrosion. These are known as stainless steel. Other types are galvanised in zinc for added protection.

Conductivity

Aluminium is a popular choice for electronic equipment thanks to its high conductivity. It’s why aluminium is typically used to make high voltage long distance power lines. In contrast, steel is a poor conductor.

Popular Uses of Aluminium and Steel

Given how ubiquitous aluminium and steel are in the manufacturing world, listing all their possible uses would be near impossible. That said, here are a few of the most common.

Aluminium Uses

• Aircraft construction
• Structural components
• Power lines
• Windows and doors
• Electronics (e.g. smartphones, computers, and TVs)
• Household appliances (e.g. refrigerators and TVs)

Steel Uses

• Buildings and infrastructure
• Factory equipment
• Cars, ships, and trains
• Medical equipment
• Pipes
• Storage and packaging

Benefits of Aluminium vs Steel

Aluminium and steel each have their own advantages, and neither is necessarily better than the other. The metal you should choose depends on what you intend to use it for.

Steel is heavier and stronger than aluminium, making it better for heavy duty purposes, while aluminium is more elastic, making it better for shaping. Aluminium’s conductivity also makes it preferable for electronics.

Of course, this is far from set in stone (or if you prefer, metal). If you’re not sure which would be best for your project, don’t hesitate to reach out to us - we’re happy to discuss your requirements and offer our professional recommendation.

Cost of Aluminium vs Steel

The price of aluminium and steel changes all the time, driven by the global market. In general, however, steel tends to be cheaper than aluminium.

Aluminium and Steel Cut to Size

Clickmetal are the UK’s premier suppliers of aluminium, stainless steel, mild steel, and galvanised steel. We cut our metals to the length you require, eliminating waste and extra labour, and have a huge range of standard and bespoke products for you to browse.

We deliver to all corners of the UK, dealing directly with both businesses and individuals. Whether you need metal for a major construction job or a small DIY project, you can trust us to provide.

Got questions about our products and services? Get in touch online or give us a call on 01794 526090 today!