What is the difference between mild steel and SS400 material

SS400 material is well known in building and structural constructions. SS400 material is a kind of mild steel. What is the difference between mild steel and SS400 material? First, we need to understand what is mild steel.

Mild steel is the mildest type of carbon steel. Its carbon content is low, which is 0.16–0.29% approximately by weight. Mild steel can contain other elements as well. For example, manganese, silicon and trace amounts of phosphorous. Those elements protect the integrity of the structure of metal iron by preventing dislocations within the iron crystals.

SS400 material belongs to mild steel. The biggest difference between mild steel and SS400 material is that mild steel is a general concept, and it covers a lot of steel grades, and SS400 is only one of them.