Aluminium Vs. Stainless Steel: Main Differences

strength

there’s no denying the fact that stainless steel is much stronger than aluminium. but this strength comes at a cost – it’s a much heavier material.

strength to weight ratio

aluminium is about one third of the weight of stainless steel – hence the reason it’s used in industries such as aeroplane and bicycle manufacturing. you’ll also find aluminium sheet widely used in the automotive sector. so, although stainless steel is stronger, the strength to weight ratio of aluminium is much better.

cost

typically, commercial quality aluminium and stainless steel are similar in price per kilogram, but due to aluminium being lighter, it often makes it more cost effective.

corrosion

stainless steel is made up of iron, chromium, nickel, manganese and copper.  the chromium is added as an agent to provide corrosion resistance.  also, because it is non-porous the resistance to corrosion is increased. aluminum has a high oxidation and corrosion resistance mainly due to its passivation layer.  when aluminum is oxidized, its surface will turn white and will sometimes pit. in some extreme acidic or base environments, aluminum may corrode rapidly with catastrophic results.

conductivity

stainless steel is a really poor conductor compared to most metals. aluminum is a very good conductor of electricity. due to its high conductance, light weight, and corrosion resistance, high-voltage overhead power lines are generally made of aluminum.

thermal properties

stainless can be used at much higher temperatures than aluminum which can become very soft above about 400 degrees.

malleability

aluminium is easier to work with: it’s relatively soft and easier to cut, stretch and manipulate. you can bend aluminium into shape without breaking it a lot easier than you can stainless steel, which, as it is harder to form, can be more difficult to work with.

effect on foods

stainless steel is less reactive with foods.  aluminum can react to foods which may affect color and flavor.

hopefully this rundown has given you an understanding of the fundamental differences between aluminium and stainless steel – for any further information, don’t hesitate to get in touch.