Mild steel vs stainless steel

The overall term steel covers a wide variety of different metals, two of the main examples being mild steel and stainless steel. Even though both stainless and mild steel include a whole sub-group of different metals, there are a few important characteristics that differentiate the two. 

What is mild steel? 

Mild steel is a type of steel made up of iron and carbon as its main components. This type of steel differs from normal steel in the sense that it contains a much lower percentage of carbon compared to standard steel. 

The carbon content of mild steel can vary from 0.05% to 0.25%, with its properties being mostly dependent on this little amount of carbon. There are several grades of mild steel, and it is often used as a building material with a number of famous skyscrapers and bridges being made from it. 

What is stainless steel? 

Stainless steel is comprised of iron and chromium and is categorised as a metal alloy. It has around 10% of chromium mixed in with the iron, with the other metal elements involved being nickel, molybdenum, titanium, and copper. Non-metal components in stainless mainly have carbon present. 

This type of steel can naturally cope with very high temperatures. For this reason, stainless steel is often used to make kitchen equipment. Unlike normal steel, it has a clean and shiny appearance which makes it attractive and appealing for consumers. 

Comparing mild steel and stainless steel 

The most prominent factor that distinguishes mild steel from stainless steel is their alloying element. As previously mentioned, mild steel is alloyed with carbon whilst the alloying element in stainless steel is chromium. These alloys produce vastly different outcomes in terms of corrosion resistance, malleability, ease of fabrication, and cost. 

Corrosion 

Due to stainless steel being alloyed with chromium, it has a significantly higher level of corrosion resistance than mild steel. The chrome within the stainless steel reacts with oxygen in the air and creates a natural ‘chromium oxide’ protective layer on the surface of the metal. This means that as long as the layer doesn’t become damaged, the metal will be resistant to corrosion. 

Different grades of stainless steel will contain different elements that make them more suitable for various environments, for example a marine environment which includes the presence of water and salt. 

By contrast, mild steel does not have a chromium oxide protective layer, meaning the iron that is present will react with the moisture to form iron oxide or rust. Therefore, additional processing will be needed during mild steel fabrication such as galvanising in order to ensure the metal is protected. 

Fabrication 

Chrome is a hard alloy, which means stainless steels are a lot stronger and resistant to impact in comparison to mild steel. However, despite stainless steel fabrication being relatively easy, it’s not as easy as mild steel metal fabrication. Mild steel is much more malleable than stainless steel, and so it is commonly used in general fabrication engineering.  

Cost 

When deciding between mild or stainless steel, cost can be an influential factor. Despite stainless steel offering a far better life span and corrosion resistance than its mild counterpart, the different alloying elements it contains (especially chromium) make it more expensive.  

If you combine that with the extra work that goes into fabricating it, stainless steel comes with a much higher price tag than mild steel. However, the benefits you get in return with stainless steel, particularly the aesthetic look, impressive rust resistance, and low maintenance, you will find that it’s very much value for money.   

At FEM, our team are experts in the field of steel fabrication in Sheffield with skills covering both mild steel fabrication and stainless steel fabrication and welding. So, no matter your project requirements we will carry out the work to the highest standard. Contact us today to find out more about how we can help you with our steel fabrication service.