Cast Steel vs Mild Steel – What’s the Difference

Cast Steel vs Mild Steel

Steel is an essential material in various industries, from construction to manufacturing. Different types of steel are available, each with its unique properties, advantages, and disadvantages. Two of the most commonly used types of steel are cast steel and mild steel. While they might seem similar, they differ in several aspects. In this blog post, we will explore their differences, strengths, and weaknesses and help you decide which type of steel is right for your project or application.

Difference Between Cast Steel and Mild Steel


Cast steel and mild steel differ in their chemical composition. Cast steel is an alloy of iron, carbon, and other elements, including silicon, manganese, and chromium. These elements are added to improve the steel’s strength, corrosion resistance, wear resistance, and other properties. On the other hand, mild steel is a low-carbon steel that contains less than 0.25% of carbon. It’s the most commonly used type of steel that is easy to weld, cut, and shape.

Strength and Durability:

Cast steel is known for its high strength, toughness, and durability. It can withstand high pressure, impact, and wear and tear, making it suitable for heavy-duty applications, such as machinery parts, valves, and pumps. Mild steel, while not as strong as cast steel, is still durable and can withstand moderate stress and strain. It’s commonly used in construction, automotive, and furniture industries.

Weldability and Machinability:

Mild steel is the most weldable type, meaning it’s easy to combine two pieces of mild steel together using various welding techniques. On the other hand, cast steel is less weldable and requires preheating and post-weld treatment to avoid defects and cracks. Similarly, mild steel is easy to machine and cut due to its low carbon content, while cast steel is harder to machine and requires special tools and techniques.

Corrosion Resistance:

Cast steel is more corrosion-resistant than mild steel due to its higher chromium and nickel content, making it suitable for applications exposed to harsh environments, such as marine and chemical industries. Mild steel, while still corrosion-resistant, requires regular maintenance and protective coatings to prevent rust and degradation.


Mild steel is generally less expensive than cast steel, making it a popular choice for applications that don’t require high strength or corrosion resistance. Due to its additional elements and manufacturing process, cast steel is more expensive but more durable and long-lasting.


In summary, while cast and mild steel are types of steel, they differ in composition, strength and durability, weldability and machinability, corrosion resistance, and cost. Choosing between the two depends on the project or application’s requirements and needs. Cast steel is ideal for heavy-duty and high-stress applications requiring high strength and durability, while mild steel is suitable for applications where cost, weldability, and machining are more critical. By understanding these differences, you can decide which type of steel to use in your next project.



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