The Key Differences Between Stainless Steel and Aluminium
Stainless steel and aluminium may look similar and are both popular materials for manufacturing, but these two metals have fundamental differences that are key factors when choosing which metal to use.
Below we highlight a few major differences between stainless steel and aluminium to help guide you when deciding which metal is ideal for your manufacturing needs.
Although stainless steel is stronger than aluminium, is also much heavier. In fact, aluminium is approximately a 1/3rd of the weight of steel, giving it a better strength to weight ratio than stainless steel. When considering tensile strength and potential (the resistance of a material to break under tension) stainless steel will always win when high strength is a priority.
This is one of the critical areas where aluminium offers a distinct advantage. As in most cases a component made from aluminium will weigh approximately a 1/3rd of the weight of an identical stainless steel component.
When creating a customized shape or component, the ability to form, shape, and otherwise manipulate the material used is a critical factor to consider. Aluminium is fairly soft and easier to cut, bend and form without breaking, due to its reduced tensile strength. Stainless steel is harder to form and its resistance to wear and abrasion can make it difficult to work with.
Stainless steel is one of the worst conductors of electricity due to its dense protective oxide layer, whilst aluminium is a very good conductor of electricity. This is also the case when it comes to heat, however stainless steel can be used at higher temperatures, whilst aluminium will soften at high temperatures.
- HEAT RESISTANCE
As mentioned under the conductivity section, stainless steel has a much better resistance to heat, with a melting point of 1,500°C in comparison to aluminium’s 660°C melting point. When it comes to cold temperatures aluminium has the advantage. While stainless steel becomes brittle in low temperatures, aluminium’s tensile strength increases.
Aluminium won’t respond to magnets as all its alloys are free from iron, while the magnetic properties of stainless steel will vary. Popular non-magnetic grades of stainless steel include 304L.
Typically, aluminium would have been far less expensive than stainless steel, but with current global market pressures, we have seen rapid price increases on aluminium. These costs will continue to fluctuate from month to month. However, our focus is to continue strategic supply chain to ensure best practices to continually offer our customers a competitive advantage.
- CORROSION RESISTANCE
When considering corrosion resistance, stainless steel is your best choice. Chromium is added to stainless steel, giving it a protective film and excellent corrosion resistance. Its non-porous characteristic also gives it an extra level of resistance. Although aluminium does not rust, it does corrode when expose to salt.
- EFFECT ON FOODS
Stainless steel is less reactive with foods than aluminium, which is why it is often used in kitchen utensils and cookware. Aluminium may react to foods, affecting the color and flavor.