Mild steel tube grades vary to suit various performance needs and applications. Each grade is tailored to deliver specific strengths, from structural integrity to ease of fabrication. Understanding these differences is key to choosing the most suitable tube for your project. With the right grade, you can ensure both efficiency and long-term reliability.
What is Mild Steel?
Mild steel, also known as carbon steel, is a widely used type of steel that contains a low percentage of carbon, typically between 0.16% and 0.29%. This modest carbon content gives it a balance of strength, flexibility and machinability, making it ideal for a wide range of industrial and construction applications.
One of the key characteristics of mild steel is its relatively high melting point, ranging from 1450°C to 1520°C. Interestingly, steels with higher carbon content tend to melt at lower temperatures. This higher melting point gives mild steel excellent ductility when heated, allowing it to be easily forged, cut, drilled and welded. Its workability makes it particularly suitable for fabrication projects where shaping and joining are essential.
While mild steel may contain small amounts of alloying elements, carbon remains its primary alloy. This simplicity in composition is part of what makes mild steel so versatile and cost-effective.
Mild steel is available in a range of grades, each offering specific properties to suit different requirements. It is also recyclable, which supports more sustainable manufacturing and construction practices. However, one limitation of mild steel is its relatively low corrosion resistance. Surface treatments such as red oxide primers, metal paints, spray coatings and zinc finishes are commonly applied to protect it from rust and extend its lifespan. These not only improve durability but can also enhance the appearance of the finished product.
Grades of Mild Steel
| Steel Grade | In % by Mass | ||||||
|---|---|---|---|---|---|---|---|
| Steel Name | Steel Number | C max. | Si max. | Mn max. | P max. | S max. | Al max. |
| E155 | 1.0033 | 0,11 | 0,35 | 0,70 | 0,025 | 0,025 | 0,015 |
| E190 | 1.0031 | 0,10 | |||||
| E195 | 1.0034 | 0,15 | 0,35 | 0,70 | 0,025 | 0,025 | 0,015 |
| E220 | 1.0215 | 0,14 | |||||
| E235 | 1.0308 | 0,17 | 0,35 | 1,20 | 0,025 | 0,025 | 0,015 |
| E260 | 1.0220 | 0,16 | |||||
| E275 | 1.0225 | 0,21 | 0,35 | 1,40 | 0,025 | 0,025 | 0,015 |
| E320 | 1.0237 | 0,20 | |||||
| E355 | 1.0580 | 0,22 | 0,55 | 1,60 | 0,025 | 0,025 | 0,020 |
| E370 | 1.0261 | 0,21 | |||||
| E420 | 1.0575 | 0,16 | 0,55 | 1,70 | 0,025 | 0,025 | 0,020 |
| E460 | 1.0435 | 0,16 | |||||
Physical Properties of Mild Steel
Mild steel’s widespread use across industries can be attributed to its excellent balance of physical properties. These characteristics make it a dependable and adaptable material for a wide range of structural, mechanical and fabrication applications.
Some of the key physical properties of mild steel include:
High tensile strength
Mild steel can withstand significant stress before deforming, making it ideal for load-bearing structures and components.
High impact strength
It absorbs energy well under sudden force or impact, reducing the risk of fracture.
Good ductility and weldability
Mild steel can be drawn out into thin wires and easily welded, allowing for a wide range of fabrication possibilities.
Magnetic properties
Due to its ferrite content, mild steel is a magnetic material, which is useful in certain mechanical and electrical applications.
Excellent malleability
It can be shaped and formed without cracking, especially under cold-forming conditions.
Heat treatment compatibility
Mild steel responds well to a variety of heat treatments, which can enhance specific properties depending on the application.
These physical attributes make mild steel a practical and cost-effective choice for everything from construction and automotive manufacturing to general engineering and custom fabrication.
Common Applications for Mild Steel Tubes
Thanks to their strength, versatility and ease of fabrication, mild steel products and tubes are used across a wide range of industries. Here are some of the most common applications:
Machinery manufacturing
Mild steel tubes are used in the production of machine frames, supports and components due to their durability and machinability.
Automobile manufacturing
They play a key role in the automotive sector, forming parts of chassis structures, exhaust systems and suspension components.
Aviation and shipbuilding
Their strength-to-weight ratio and weldability make mild steel tubes suitable for structural and support elements in both aircraft and marine vessels.
Furniture manufacturing
Mild steel tubes offer both structural support and aesthetic appeal in the production of modern and industrial-style furniture.
Fitness equipment
The high impact strength of mild steel makes it a reliable material for gym machines, weight racks and training apparatus.
Industrial pipes
Mild steel tubes are widely used for transporting fluids and gases in manufacturing and processing environments.
Construction field
From scaffolding and support beams to architectural frameworks, mild steel tubes are essential in building infrastructure.
Agricultural field
Durable and easy to fabricate, they are often used in equipment frames, fencing and irrigation systems.
Transportation facilities
Mild steel tubing is commonly found in railings, barriers and support structures in public transport systems.
Marine engineering
Despite its need for protective coatings, mild steel is still used in marine applications for structural components above the waterline.