Mild Steel Vs Stainless Steel: What’s The Difference?
The market of metal fabrication services can be hard to navigate, especially when it comes to choosing the right metal for your project.
Committing to thorough research is your best bet, but this can be hard to perform when managing a project and/or your business. And sometimes, you just need the answer to whether one metal is more effective than another – such as mild steel vs stainless steel.
If you’re currently in this position and don’t know where to start, we’ve got you covered in our blog below. We’ll discuss the difference between mild steel and stainless steel, their varying properties, and their applications.
What is mild steel?
Mild steel is a metal-containing iron (meaning it’s ferrous) and is widely regarded within the sheet metal industry as suitable for a variety of engineering applications. As it is a type of carbon steel that has a low amount of carbon, it makes it easier to shape and machine.
What is stainless steel?
A solid metal alloy, stainless steel is made of iron, carbon, and other types of metals – typically chromium, nickel, and nitrogen. This helps make it a metal that can endure corrosion more than other types, so is perfect for specific applications – such as cookware manufacturing and medical instruments.
Mild steel vs stainless steel: corrosion
Let’s take a look at the difference between mild steel and stainless steel when it comes to both types of corrosion properties:
Mild steel corrosion
Mild steel does not have corrosion resistance. In fact, mild steel has to undergo a galvanisation process to prevent it from corroding. This is the act of coating a metal with zinc to help it avoid rusting. If mild steel doesn’t get galvanised, it will likely need more maintenance as the metal could potentially be weakened.
Stainless steel corrosion
As the name suggests, stainless steel is corrosion-resistant (hence stainless). This is due to the chromium it contains. This typically amounts to 10% and reacts with the oxygen in the air to form a protective layer – which makes it resistant to corrosion and rusting.
Mild steel vs stainless steel: strength
Is stainless steel harder than mild steel? We’ll explore this and the strength of both below:
Mild steel strength
The tensile strength (the amount of force a metal can withstand before it breaks/stretches) of mild steel is usually between 400 and 550 MPa – so a fairly average level. Its yield strength (the amount of stress the metal can take before it begins to deform plastically) is around 250 – 350 MPa.
Stainless steel strength
As there are 100s of types of stainless steel, the strength of it depends on the type of alloy used and its condition. In terms of tensile strength, this typically ranges from 500-720 MPa. For example, 304 stainless steel can reach a maximum of 625 MPa, meanwhile, its yield strength is approximately 205 MPa.
Mild steel vs stainless steel: weldability
Weldability refers to a metal’s ability to be welded without cracking or causing other defects.
Read on to see the comparison of mild and stainless steel when it comes to the different types of welding:
Mild steel weldability
As a result of its low ductility, mild steel is flexible and therefore easy to weld. When welding mild steel, it’s important to wear proper PPE to avoid exposure to welding fume; this can cause health problems such as lung cancer.
Stainless steel weldability
Whilst stainless steel is weldable, it can be harder to weld than other types of steel – such as carbon steel. Generally, mild steel is easier to weld, but stainless steel can be welded using special arc processes, such as TIG welding.
Mild steel vs stainless steel: malleability
A metal’s ability to be shaped without cracking is called malleability. Below we’ll explore the malleability of both mild and stainless steel below:
Mild steel malleability
Overall, mild steel is much more malleable than stainless steel. Again, this is the result of its low carbon content, which makes it easy to shape and bend. As a result, it’s the preferred choice for complex metal–forming projects.
Stainless steel malleability
Grade 304 and 316 stainless steel are the most malleable types of steel available, as they have a high nickel content. This means they are more suitable to be shaped without cracking – making them ideal for precise and intricate applications.
Mild steel vs stainless steel: applications
Now we’ve explored the differences between mild and stainless steel when it comes to their properties, let’s dive into the applications they’re best used for:
Stainless steel applications
There are a variety of applications in which stainless steel can be used. For example, It’s used in cookware because it has high heat resistance – and is easy to clean. What’s more, in the medical industry, it is used to create medical instruments as it is easier to sterilise than other types of metals.
Mild steel applications
Mild steel is used in a variety of industries, including construction, manufacturing, and automotive. It’s a popular choice due to its weldability, and its ability to be cut and coated in a bunch of different ways.
Mild steel vs stainless steel: cost comparison
Finally, let’s take a look at the most important factor pertaining to using a metal – the cost.
The cost of mild steel
Overall, the initial cost of mild steel is cheaper than stainless steel. This is because of its simpler composition and availability. However, it’s important to factor in the cost of maintenance as it is prone to corrosion.
The cost of stainless steel
As mentioned, stainless steel is more expensive as a result of the added alloying elements. For example, the addition of chromium to aid it in providing ultimate corrosion resistance. But over time, it will require less maintenance because of this resistance.
So…which one is better?
Overall, the most suitable option for you between mild steel and stainless steel depends on what you plan on using it for. Whilst mild steel is easier to weld and malleable, it is prone to corrosion, whereas stainless steel offers the opposite factors.
Ultimately, if you’re looking for a low-cost and low-maintenance solution, mild steel that has been galvanised is probably your best bet.
Work with Salamander Fabrications for cost-effective projects with precise results
At Salamander Fabrications, we’ve been in the sheet metal industry for over 40 years, and have seen a variety of projects come to life in that time. So when you need advice about which metal to choose for your specific project, we know what will suit your needs best.
When you work with us, our experts will be able to help your projects come to life with ISO-accredited services from CAD to welding.
Interested? Get in touch with our team of experts today.
