Carbon steel can be divided into carbon structural steel, carbon tool steel and free cutting structural steel, carbon structural steel is divided into engineering construction steel and machine manufacturing structural steel.

Mainly refers to the carbon content of less than 2.11% without special alloying elements. Sometimes called plain carbon steel or carbon steel. Carbon steel, also known as carbon steel, refers to iron carbon alloy with carbon Wc less than 2.11%. Carbon steel in addition to carbon generally also contains a small amount of silicon, manganese, sulfur, phosphorus.