Should I use Aluminum or Stainless Steel for my project?

One question we’re often asked is: “Should I use stainless steel or aluminum?”

We also see, pretty often, people making the choice between these two metals.

So, what follows are some tips and guidelines for deciding if you should be using aluminum or stainless steel.

  • Strength – Strictly speaking, stainless steel is stronger than Aluminum (*see below).
  • Strength to weight ratio – Aluminum is not as strong as stainless steel, but it’s also 1/3 of the weight.  This means that a pound of aluminum is stronger than a pound of steel.
    • Unless you need the full strength of stainless steel, aluminum might be a better option.
  • Corrosion – Stainless steel is an alloy of iron, chromium, nickel, manganese and copper.  Chromium and the non-porous nature of steel are responsible for its corrosion resistance.  Aluminum gets its corrosion resistance from its passivation layer.  However, it also has high oxidation and when oxidized will turn white and pit.  In extreme acidic or base environments, aluminum corrodes quickly.
    • Keep the main working environment in mind and choose your metal accordingly.
  • Thermal Conductivity – Aluminum conducts heat a lot better than stainless steel, which is why it’s used for car radiators, ACs and heat sinks.
    • If heat conduction is essential or advantageous, aluminum might be the way to go.
  • Working Temperature – Stainless has a much higher working temperature than Aluminum, which becomes extremely soft at 400 degrees.
    • If you need high working temperatures, choose stainless steel.
  • Workability – Aluminum is malleable and easy to cut/shape. Stainless steel is designed for high resistance abrasion and forming.
    • If your product requires intricate cutting and shaping, aluminum will be much easier to do this.
  • Welding – Stainless can be welded without any issues, aluminum, not so much.
    • If your product will be welded, choose stainless steel.
  • Electrical Conductivity – Stainless steel is one of the worst conducting metals. Aluminum is one of the best.
    • If conducting electricity is critical, aluminum is what you need.
  • Effect on Foods – Stainless steel doesn’t usually interact with foodstuffs.  Aluminum could possibly change the taste and/or color.
    • If you’re working with food, stainless steel is the best choice.
  • Cost – In most situations, aluminum is cheaper than stainless steel.

If you’re still not sure which material you should be using, fill out the contact form below and one of our engineers will reach out to you to help you decide.

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