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Galvanized Steel Vs. Stainless Steel: Which is Better?

Chicago's stainless steel BEAN sculpture

In the battle of galvanized steel vs. stainless steel, which comes out on top? Plain steel corrodes and is susceptible to the elements. So it’s modified into many forms in order to withstand the elements. The two most popular forms of steel are galvanized and stainless. Each one has their pros and cons. This article will take a close look at both galvanized steel and stainless steel so that you can make an informed decision before spending money.

Stainless Steel

Stainless steel is developed by adding alloying elements during its development. By adding chromium, stainless steel becomes highly resistant to corrosion. There are also additional elements added depending on the quality of the steel that make it even more durable.

Galvanized Steel

Galvanized steel is coated with a layer of zinc to protect the steel from the elements. It’s a very thin layer that’s added once the steel has been refined and shaped. The inner steel is essentially sealed away from the elements.

Stainless Steel vs. Galvanized Steel: How they Resist Corrosion

Steel corrodes when the iron inside comes into contact with oxygen. The protection from stainless steel comes from the chromium that’s added during its development. It provides a protective composition of chromium oxide by combining with oxygen before it reaches the iron. This protection prevents rust from forming as long as enough chromium remains in the steel.

Stainless steel comes in different grades depending on the amount of chromium it contains. Higher grades contain more chromium so they are more resistant to corrosion.

Galvanized steel works differently. The layer of zinc coating the outside of the steel protects it from oxygen. Even if slightly damaged, the remaining zinc will continue to handle the oxygen. This offers further protection.

 Galvanized steel building facade

What’s the Biggest Difference?

The biggest difference when comparing stainless steel vs. galvanized steel is quality, cost, and aesthetic appeal.

Stainless steel offers better protection against corrosion because the protection is embedded into the steel plate. Even if it’s scratched or damaged, chromium’s resistance is not affected.

On the other hand, if galvanized steel is damaged too much, the iron is exposed to the elements. While a small scratch isn’t going to have an impact, a large enough cut will cause it to rust. The biggest problem is that galvanized steel is usually made in large sheets and then cut. This leaves the edges vulnerable.

It’s also worth mentioning that stainless steel is considered to be much more aesthetically pleasing than its galvanized steel counterpart.

So what, then, are the benefits of galvanization? It offers a lot of protection at a much lower price. There are specific applications where each type of steel plays a role.

Common Applications of Stainless Steel

If corrosion is a major concern, then stainless steel must be used to offer the most protection. Some examples include:

  •      Equipment used to process food
  •      Eating utensils
  •      Aerospace components, especially engine parts
  •      Equipment used to manufacture medicine
  •      Essential safety fasteners

Common Applications of Galvanized Steel

If corrosion and aesthetic appeal are not a concern, then the less expensive option is used. Here are some examples:

  •     Air conditioning and/or heating ducts
  •     Fasteners that are not considered essential to safety
  •     Safety railings
  •     Signs

Stainless Steel vs. Galvanized Steel: Which is Stronger?

We need to look closely at how steel strength is measured in order to answer this question. The most effective metric is tensile strength – a number that conveys steel’s resistance under tension.

Carbon steel measures at 841 megapascals. In comparison, structural steel comes in 400 megapascals. Both of these types of steel are used in the creation of galvanized steel. Since the process used to galvanize steel doesn’t affect its tensile strength, we can use this metric to determine that galvanized steel is stronger than stainless steel.

Which Type of Steel is Heavier?

Both stainless steel and galvanized steel weigh about the same. There might be small differences depending on the exact makeup of alloys used in its creation and the amount of coating used. Obviously thickly coated galvanized steel is heavier.

But overall, there is no noticeable difference in weight between the two types of steel.

Can Stainless and Galvanized Steel be Welded?

Both are able to be welded but each type of steel comes with its own set of welding considerations. With stainless steel, welding can compromise the passive protective layer and make the steel more brittle. It reduces the corrosion resistance and lowers its overall integrity. Pickling treatments are used to reduce this negative impact by reducing the heat exposure in the stainless steel.

Galvanized steel isn’t negatively impacted by welding, but the protective layer releases a handful of zinc oxide fumes when heated. So you must have proper ventilation when welding galvanized steel.

The Final Verdict

The application of steel is the deciding factor when making a choice of stainless steel vs. galvanized steel. When aesthetics and overall protection are absolutely essential, then stainless steel is the go-to choice. But due to its lower price, if neither of those play a role, then galvanized steel is used.