Aluminum vs Stainless Steel: Which is Better?

What are the differences between aluminum and stainless steel?

1. Durability
2. Strength to weight ratio
3. Cost-effectiveness
4. Thermal conductivity
5. Machinability
6. Corrosion-resistance

When it comes to aluminum vs stainless steel, the two materials do have their similarities, especially when it comes to appearance and corrosion-resistance. However, they do have a number of differences in durability, strength-to-weight-ratio, cost-effectiveness, conductivity, and machinability. Before you choose which type of material is the best for any kind of purpose — be it decorative, consumer good, or structural — knowing these key differences will help. Read on to learn more.

Durability

Stainless steel is much stronger than aluminum due to the latter’s high chromium content. Depending on the grade of the stainless steel, the material can have a chromium content of anywhere between 10.5% to 18%. This is the alloying metal that drastically improves the hardness, tensile strength, as well as corrosion resistance.

While stainless steel may be stronger than aluminum, the former does have its drawbacks. It is a considerably much heavier material, which may not be ideal for all kinds of applications such as automotive and aircraft component manufacturing. Aluminum is around 33% lighter than stainless steel, making it an ideal metal replacement for industries that want to focus on reducing the weight of different products. 

Strength To Weight Ratio

As mentioned before, aluminum might not have similar strength properties compared to steel, but it does have a weight advantage and a better strength-to-weight ratio. This simply means that for every volume of aluminum, the strength-to-weight ratio, or specific strength are 12.5% for aluminum, and 6.25% for stainless steel. 

If you’re using either aluminum or stainless steel for any kind of application, take note that you’ll be getting better strength when you make use of aluminum. 

Choosing aluminum for applications such as wall cladding/panelling, railings, shelves, roofing, moldings, and the like, will provide the structure with more benefits compared to stainless steel. 

Cost-Effectiveness

Aluminum is cheaper than stainless steel. Tons of factors can influence this, such as ore market growth, natural abundance of the material, ease of manufacturing, and many more. Stainless steel products would become more expensive in this regard because of the presence of other alloying metals like manganese, chromium, iron, nickel, and copper. 

When it comes to budget considerations, it’s better to choose aluminum. In this way, you’ll be able to save up more and lower your material costs. Aluminum products and accessories like beams, railings, tubings, and the like are also lighter in weight, making them easier to install and minimizing potential costs on product damage.

Thermal Conductivity

One of the poorest heat conductors is stainless steel, making it a non-suitable material for products such as heat sinks and large-scale applications like electrical power lines. Compare this to aluminum, which has excellent thermal conductivity and can be used in different consumer goods like heat sinks, motherboards, wiring, and electrical conduits, among many others. 

However, aluminum does have a lower melting point compared to stainless steel. For aluminum, the value is at 660 degrees Celsius, compared to the 1375 to 1530 degrees Celsius of stainless steel. Keep this in mind when using aluminum in high thermal uses that may cause the product to deform or soften. 

Machinability

Since aluminum is lighter, it is easier to cut, bend, fold, and modify than stainless steel. This gives the material its high machinable properties that allow for further processing. If your aluminum or stainless steel products need to be cut in order to meet size requirements, it’s a much more efficient process when it comes to aluminum.

For example, let’s say that you have a small construction or building project. When there’s a need to make alterations in the size of the components, using aluminum materials makes the job easier. 

Corrosion-Resistance

Both materials exhibit exceptional corrosion-resistance, but you do have to take other factors into consideration, such as weight, size, strength, cost, and conductivity. 

While stainless steel may not easily rust and deform when exposed to the elements, it is an expensive material. If you’re not necessarily particular about the strength, then using aluminum instead is the better choice. If you’re worried about prolonged outdoor exposure, you can also choose to have your aluminum products protected through powder coating that does not only increase its shelf life, but also offers an aesthetically-appealing coating choice. 

Key Takeaway

In choosing between aluminum vs stainless steel, you need to understand each of the material’s properties. In this guide, we’ve outlined several of these, like the durability, strength to weight ratio, corrosion-resistance, cost, machinability, and conductivity. 

While it is true that stainless steel is stronger compared to aluminum, it does fall short on the other factors. In this case, you can benefit more from choosing aluminum as it is more budget-friendly and provides you more freedom in product modification. 

In need of high-quality aluminum products? AMC Aluminum’s selection of aluminum accessories are durable and built to last. Check them out here! You can also request a quotation for your own custom-made aluminum project by contacting them.