Low-carbon steel is also known as mild steel or soft steel. It contains a low amount of carbon, typically less than 0.3%, which makes it more malleable and ductile compared to other types of steel. Other synonyms for low-carbon steel include plain carbon steel, commercial steel, and structural steel. Plain carbon steel refers to any steel that has carbon as the primary alloying element. Commercial steel is a term used for low-carbon steel that is commonly used in industries such as construction and manufacturing. Structural steel is a type of low-carbon steel that is specifically designed for use in construction projects due to its high strength and durability.