Our Mild Steel Plates is a steel in everyday use which will rust (ie. it is not stainless steel). Many people have made reference to the carbon content of mild steel and unless you know what this does then it is pointless. Low carbon steel such as mild steel will be quite soft and Higher carbon steels (up to about 0.9%) can be hardened using a method of heating and quenching (fast cooling in oil or brine) to a point where they can be used for cutting other steels, you would know high carbon steel as a drill bit or lathe tool.