Is Mild Steel Magnetic? Varieties and Magnetism Explained

is mild steel magnetic?

Mild steel is a popular choice in the construction and manufacturing sectors due to its malleability, durability, and affordability.

A frequently asked question regarding this material is: “Is all mild steel magnetic?” To fully answer this, we’ll delve into the properties of mild steel, its various types, and its magnetic attributes.

Let’s get into it…

The Basic Science: Magnetism in Metals

It is important to understand why some metals are magnetic and others are not before discussing the magnetism of mild steel. The motion of electrons, particularly their spin, causes magnetism.

An unpaired electron in a metal like iron aligns with its spin in the presence of a magnetic field, making it attracted to magnets.

What Is Mild Steel?

Compared to high carbon steel, mild steel has a lower carbon content (typically 0.05–0.30%) which makes it more malleable and ductile. Its magnetic properties are due to the iron content, which is the predominant element in mild steel.

Is Mild Steel Magnetic?

The answer is yes, mild steel is magnetic. Steel itself is magnetic due to its high iron content, which aligns the unpaired electrons in the atoms when exposed to a magnetic field. While the strength of mild steel’s magnetism can vary based on its exact composition and processing, this property remains consistent across most types.

Understanding the Key Grades of Mild Steel

Mild steel, known for its versatility and formability, is not a singular entity. As a result, it comes in a variety of grades, each tailored to a specific purpose based on its chemical composition and properties. Below is a breakdown of the key types of mild steel, ensuring you choose the right one for your project.

Grade 250 (G250) Steel:

  • Composition: Typically consists of 0.12% carbon, 0.4% manganese, 0.04% phosphorous, 0.05% sulfur.
  • Properties: Known for good formability and weldability.
  • Applications: Widely used in structural and general fabrication.

Grade 350 (G350) Steel:

  • Composition: Contains approximately 0.15% carbon, 0.9% manganese, 0.04% phosphorous, 0.05% sulfur.
  • Properties: Higher strength compared to G250. Still maintains good formability.
  • Applications: Suitable for load-bearing structures, bridges, and platforms.

Grade A Steel:

  • Composition: Generally consists of 0.14-0.20% carbon, 0.60% manganese max.
  • Properties: Combines ease of welding with increased strength.
  • Applications: Typically used in shipbuilding due to its corrosion resistance.

EN1A (220M07):

  • Composition: Low carbon-manganese free-cutting steel, with traces of lead.
  • Properties: Excellent machinability, good case hardening, and fairly weak weldability.
  • Applications: Ideal for the manufacture of screws, nuts, and general machinery parts.

EN3B (070M20):

  • Composition: Basic medium carbon steel with 0.25% carbon, 0.70% manganese.
  • Properties: Offers a balanced combination of strength and ductility.
  • Applications: Popular for general engineering purposes such as shafts and axles.

EN8 (080M40):

  • Composition: Medium carbon steel with 0.36-0.44% carbon and 0.60-1.00% manganese.
  • Properties: Known for its good tensile strength and ability to be heat treated.
  • Applications: Often used for parts like shafts, stressed pins, studs, keys, etc.

S275 & S275JR:

  • Composition: Carbon steel with up to 0.21% carbon content and a mix of manganese, phosphorous, sulfur, and silicon.
  • Properties: Renowned for excellent machinability and weldability.
  • Applications: Primarily used in structural and engineering projects.


  • Composition: Low carbon steel with roughly 0.20% carbon, balanced with manganese, silicon, sulfur, and phosphorous.
  • Properties: High tensile strength and yield strength.
  • Applications: Suitable for construction, bridges, and in heavy load-bearing structures.

Ensure the success of your project by understanding the specific grades of mild steel. Building a complex structure or crafting a specific part requires balancing formability, strength, weldability, and corrosion resistance. If in doubt, consult metallurgists or experts, and remember that the grade you choose will have a significant effect on the product’s longevity and performance.

Our Standard Steel Options

Let’s explore the different forms of mild steel that we stock and how their magnetism comes into play:

Mild Steel Angle Section 60mm x 60mm Length x 6mm Thick


As the name suggests, this is an L-shaped product used primarily in construction and fabrication. It retains the magnetic properties inherent to mild steel.

Perforated Metal

This form of mild steel has holes punched, drilled, or stamped into it, creating a patterned sheet. The perforations don’t alter the fundamental magnetic properties of the steel.

Mild Steel 10mm Square Hole Perforated Mesh x 14mm Pitch x 1.5mm Thick Image
Plain Mild Steel Round Tube Pipe Group Image

Round Tube

Circular hollow sections used in construction, transportation, and other sectors. The fact that it’s hollow doesn’t interfere with its magnetic properties.

Sheet Metal

A thin, flat piece of steel used in myriad applications. Its magnetic attributes are similar to other forms of mild steel.

150mm Width x 10mm Thick Flat Bar Mild Steel Section
200mm Width x 10mm Hot Rolled Mild Steel Flat Bar Section

Flat Bar

These are flat, rectangular bars of mild steel. Their broad, flat surfaces are excellent for magnetic applications.

Box Section

Also known as square or rectangular hollow sections, they are primarily used in construction. Like round tubes, their hollow nature doesn’t impact their magnetic properties.

Applications Relying on Mild Steel’s Magnetism

The magnetic properties of mild steel make it a versatile and vital material in many industries. Perforated metal, sheet, angle, round tube, flat bar, and box sections all maintain consistent magnetic properties, making them suitable for applications requiring magnetic repulsion.

Whether you’re designing a product or working on a construction project, our extensive selection of mild steel options can meet your needs. Browse our inventory to find the perfect fit for your requirements, and remember that mild steel’s magnetic properties add functionality, testing simplicity, and versatility.

Mild steel’s magnetic nature has several practical implications. Electromagnets, transformers, and motor cores frequently use it. Its ability to become magnetized and demagnetized quickly makes mild steel invaluable in these applications.

Additionally, mild steel’s magnetism makes testing and quality assurance easier. A simple magnet test can be used to distinguish mild steel from other non-magnetic metals.

As always, thank you for checking out our blog. We hope that this helps you with your project. 

Please also check out the other articles in our helpful guide series. We have written about aluminium sheeting and checker plate recently to name but two of our articles.

We are also proud to sell this product on our highly popular eBay store, check us out there too.

If you have any further questions, feel free to contact us.



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