Mild Steel vs Carbon Steel: What is the Difference?

Steel is the most used material in construction, manufacturing, and industry. Two of the most commonly used types of steel are mild steel and carbon steel.

While both are used for similar purposes, there are several key differences between the two that make them better suited for different applications.

In this article, we will take a closer look at mild steel and carbon steel and examine the differences between them, including their carbon content, mechanical properties, and manufacturing and finishing processes.

Whether you are a metal fabricator, engineer, or just looking to better understand mild steel and carbon steel, we will provide you with all the information you need to make an informed decision.

What are carbon steel sheets used for?

Low carbon steel plates are often used as a general-purpose tooling metal because of its mechanical structure and ease of machinability. Hot rolled carbon steel plate and sheet are ideal for drilling, grinding, and tapping. Carbon steel also provides exceptional welding properties for a range of applications.

What is mild steel?

Mild steel is a type of carbon steel with a low carbon content, typically ranging from 0.05% to 0.25%. These steels are also known as "low carbon steels." Mild steel is a relatively inexpensive and versatile material, commonly used in various construction and manufacturing applications.

The low carbon content of mild steel makes it more ductile and easier to shape, form, and weld compared to other types of steel. This enhanced ductility and formability allow it to be easily drilled, cut, and fabricated into various shapes and sizes.

In addition to its workability, mild steel possesses a relatively high tensile strength, making it suitable for use in high-stress applications such as beams, columns, and machinery components. Its combination of versatility and affordability makes mild steel a popular choice for a wide range of uses.

What is carbon steel?

Carbon steel is a type of steel that contains carbon as the main alloying element, with other elements present in smaller amounts. This metal is commonly used in the manufacturing of many products and structures due to its high strength and low cost.

Carbon steel can be further classified into various grades based on its chemical composition and mechanical properties. These grades include low carbon steel (like mild steel), medium carbon steel, high carbon steel, and ultra-high carbon steel. Each grade serves specific uses and applications, depending on the desired properties of the final product.

Medium to high carbon steel is frequently employed in the manufacture of machinery components such as gears, crankshafts, and shafts. Its notable strength and high hardness make it well-suited for a diverse array of tooling applications.

Carbon steel types

There are several types of carbon steel, each with unique properties and applications. These types include:

Low carbon steel

Also known as "mild steel," this type of steel has a low carbon content, making it more ductile and easier to shape, form, and weld compared to other carbon steel types. These qualities make mild steel a popular choice for construction and manufacturing applications.

Medium carbon steel

Containing 0.3% to 0.6% carbon content, medium carbon steel is stronger and harder than low-carbon steel but also more brittle. It finds use in applications requiring a balance of strength and ductility, such as machinery components, automotive parts, and building frames.

High carbon steel

With a carbon content ranging from 0.6% to 1.5%, high carbon steel is renowned for its exceptional strength and hardness. However, it is more brittle than medium-carbon steel. High carbon steel is typically used in applications demanding high strength, such as knife blades, hand tools, and springs.

Is carbon steel better than mild steel?

Both types of carbon steel have their own unique properties and advantages that make them more suitable for some applications than others. The choice between them typically depends on specific requirements.

Hot rolled mild steel sheet is preferable for low-stress applications due to its ease of fabrication and lower cost, whereas carbon steel (ranging from medium carbon to ultra high carbon) excels in high-strength applications due to its higher carbon content and resultant strength.

Carbon steel offers a significant strength advantage over mild steel, potentially being up to 20% stronger, which makes it ideal for applications requiring high strength or hardness.

However, one significant drawback of carbon steel is its higher cost. The increased carbon content leads to higher manufacturing costs compared to mild steel.

Additionally, carbon steel is more challenging to weld than mild steel, which can limit its suitability for welding applications.