what is mild steel
- Mild steel usually means a soft, unhardened steel of low carbon content, like 0.2 percent. This is what I-beams and structural elements for buildings are made of. - Carbon steel usually means steel with carbon only, in other words a non stainless steel. It may be mild steel, but not necessarily.ild steel is low carbon steel with a variety of applications. The major disadvantage is the poor resistance to corrosion. A. Mild steel is the most common form of steel. Mild steel means-steel with less than 0.15% carbon low-carbon steel, soft-cast steel.