Weathering Steel or Mild Steel: what's the difference?

Weathering Steel or Mild Steel: what's the difference?

Weathering Steel or Mild Steel: what's the difference?

We talk a lot about weathering steel, and it is the material we use in the vast majority of our range. We love it due to the beautiful patina you get when left out in the elements and because it requires zero maintenance. There are a few different brands of weathering steel, with the most commonly known being COR-TEN (or Corten).  We use an Australian-made alternative called REDCOR. 

But Amy, what about the other alternative you offer? Why offer it at all if you love the weathering steel so much?

Before I can give you that answer, let's learn a little more about each of the main materials we use:

Both steels start out in the grey colour. When comparing them in their raw form side-by-side it is unlikely you will be able to tell the difference.

Weathering Steel

Weathering steel is known for its superior corrosion resistance and thickness, and develops a stable oxide layer on the surface of the steel known as the 'patina'. In other words, the steel is allowed to rust in order to protect itself. This protective surface layer continues to regenerate over years of exposure.

When detailed correctly and exposed to alternating wet and dry conditions, the colour of the patina changes organically over time, giving it a striking appearance, even evoking images such as the red Australian outback  landscape.

Mild Steel

Mild Steel is a ferrous metal made from Iron and Carbon, and is actually a form of Low-carbon steel. Mild steel doesn’t form an oxide layer when exposed to the elements. As a result, it begins to rust immediately when moisture gets in.  Although Mild Steel can develop the much admired warm and varied brown tones and belongs to the family of weathering steels, it will leak rust onto adjacent surfaces. 

We tend to use mild steel when we know your sign will be painted or powder-coated.

What does this mean for you?

So why do we offer mild steel at all if we prefer the weathering steel so much  Most of it comes down to personal preference, and we like to offer you choice!


Feel free to send us an email if you have any other questions about the different materials we use.