When you choose a steel for your project it is necessary to know your options well. Corten steel sheet and mild steel sheet are among the two popular options, and they serve different purposes. Even though they look similar, their uses and properties are quite different. Having detailed knowledge of the same will help you choose the right steel for your requirements.
What is Mild Steel?
Mild steel is a type of carbon steel sheet with a low amount of carbon, usually less than 0.3%. The carbon amount makes mild steel sheet soft, easy to bend, cut and weld. MS is used for many applications, and it is affordable, from construction to manufacturing. Mild steel can rust quickly if exposed to moisture and air when not protected, meaning it needs to be painted, coated and treated to last longer.
What is Corten Steel?
Corten steel, aka weathering steel, is manufactured to resist corrosion. When exposed to weather, it forms a thin protective layer on its surface naturally. This layer sticks to the metal and prevents corrosion. Because of this protective coating, corten steel is a good choice for outdoor applications where regular maintenance is not easy. CS also forms a unique rusty look that many find attractive.
Comparing Corten Steel Sheets and Mild Steel
Corrosion Resistance
Corten Steel Sheets:
Corten steel forms a protective rust layer that prevents deep corrosion. This rust layer acts like a shield, stopping water and air from reaching the metal below. Over time, this means corten steel lasts much longer outside without needing paint or treatment. It’s designed for harsh weather and can stand up to rain, snow, and sun without losing strength.
Mild Steel Sheets:
Mild steel is prone to rust as soon as it is exposed to moisture and air. Without a protective coating or paint, rust can quickly spread and eat through the metal. This makes mild steel less suitable for outdoor use unless it’s properly treated. Maintenance, like repainting or galvanising, is necessary to keep mild steel in good shape.
Appearance
Corten Steel Sheets:
The surface of corten steel changes colour over time, developing a warm, rusty orange-brown patina. This weathered look is smooth and even, often appreciated for its natural, earthy style. Many architects and designers choose corten steel for its unique appearance, which blends well with natural surroundings and modern designs alike.
Mild Steel Sheets:
Mild steel starts with a bright metallic shine but quickly turns dull and red as rust forms. The rust on mild steel is flaky and uneven, which can damage the steel underneath if left unchecked. The appearance of rusted mild steel is generally considered unattractive unless it is intentionally treated or coated.
Maintenance
Corten Steel Sheets:
Corten steel requires very little maintenance because the rust layer protects it from further damage. It doesn’t need to be painted or treated regularly, which saves time and money over its lifespan. This low-maintenance quality makes corten steel especially useful for outdoor structures where upkeep is difficult or costly.
Mild Steel Sheets:
Mild steel needs regular maintenance to avoid rust. This usually means applying paint or coatings that protect the surface from moisture. If the protective layer wears off or gets damaged, rust can start forming quickly. Maintaining mild steel can be time-consuming and increase the overall cost of a project.
Cost
Corten Steel Sheets:
Corten steel is more expensive at the start because of its special alloy mix that helps resist corrosion. The upfront price is higher compared to mild steel. However, because it needs less maintenance and no painting, the long-term costs are often lower. This makes corten steel a cost-effective option for outdoor uses.
Mild Steel Sheets:
Mild steel is cheaper to buy and easier to source. It’s a popular choice when budgets are tight. But since it needs protective coatings and regular upkeep, these extra costs add up over time. So, while mild steel looks affordable initially, maintenance expenses can increase its lifetime cost.
Durability and Strength
Corten Steel Sheets:
Corten steel is very durable, especially in outdoor settings. The protective rust layer shields it from deep corrosion, helping it keep its strength over many years. This makes corten steel suitable for bridges, sculptures, and building facades where long life is important. It can withstand tough weather without losing shape or strength.
Mild Steel Sheets:
Mild steel is strong but vulnerable to rust damage. If rust penetrates deeply, it weakens the metal and reduces its lifespan. In environments with high moisture or chemicals, mild steel may need extra protection to remain durable. For indoor or covered projects, mild steel’s strength is usually enough.
Applications
Corten Steel Sheets:
Because of its corrosion resistance and unique look, corten steel is popular for outdoor architecture, sculptures, landscaping, bridges, and facades. It fits well in modern designs and projects where natural weathering is a feature, not a flaw. It’s often used where minimal maintenance is a priority.
Mild Steel Sheets:
Mild steel is widely used in general construction, machinery, vehicles, pipes, and indoor projects. It’s favored for its cost-effectiveness and ease of fabrication. However, it usually needs painting or coating to prevent rust, especially if exposed to moisture.
Which One Should You Choose?
If your project is indoors, budget-sensitive, or in a protected environment, mild steel is a good choice. It’s easy to work with and affordable. But if you want steel that lasts outdoors without much maintenance and don’t mind paying more initially, corten steel is better. Its natural rust layer keeps it safe from weather damage and adds a unique look.
Conclusion
Mild steel sheet and corten steel sheets serve different needs. Mild steel is cheap and versatile but requires care to stop rust. Corten steel costs more upfront but lasts longer outdoors with little upkeep. The best choice depends on where you’ll use the steel and how much maintenance you want to do. Understanding these differences helps you pick the right steel and get the best value.
