Mild Steel vs. Graded Steel

Mild steel and graded steel are two different types of steel that vary in terms of their composition, properties, and applications.

Mild steel, also known as plain carbon steel, is a low carbon steel that contains approximately 0.05-0.25% carbon by weight. Mild steel is commonly classified as CSA or CSB steel.  It is the most commonly used form of steel due to its relatively low cost, ease of manufacturing, and versatility. Mild steel has a relatively low tensile strength and is not as strong as graded steel, but it is more ductile and malleable, making it easier to work with. Mild steel is widely used in construction, automotive manufacturing, and general engineering applications.

Graded steel, on the other hand, is a high-strength steel that has been alloyed with various metals to improve its strength, toughness, and durability.   The alloying elements used in graded steel can vary, but typically include manganese, nickel, chromium, and molybdenum. Graded steel has a higher tensile strength. However, graded steel is more expensive than mild steel and can be more difficult to work with due to its hardness.  Grade 50, 55 and 80 are commonly referred as types of graded steel.

In terms of their applications, mild steel is commonly used in applications where strength is not the primary consideration. Mild steel is also a preferred option when a project requires ductility and malleability such as bent shapes.  Graded steel, on the other hand, is used in applications where high strength, loads and spans are essential, such as in roofing and decking.

Prior to ordering flat sheets, its critical to first examine the end use.  For complicated bent parts, mild steel may be the preferred option.  Although modern machinery can now bend both graded and mild steel, some press brakes cannot bend graded steel without fracturing the steel.  Please check with your machine manufacturer to determine your machine's capabilities.

In summary, mild steel and graded steel are two different types of steel with varying properties and applications. Mild steel is a low carbon steel that is easy to work with and is commonly used in bent shape applications, while graded steel is a high-strength steel that is more expensive but is used in applications where high strength and load capability is essential.