Carbon steel is an iron-carbon alloy with a carbon content of 0.0218% to 2.11%, also called carbon steel. Generally, it also contains a small amount of silicon, manganese, sulfur, and phosphorus. Carbon steel can be divided into three categories: carbon structural steel, carbon tool steel and free-cutting structural steel. Carbon structural steel is further divided into engineering construction steel and machine-manufactured structural steel. According to the carbon content ,carbon steel can be divided into three categories. Steel is divided into low carbon steel (WC < 0.25%), medium carbon steel (WC0.25%-0.6%)and high carbon steel (WC>0.6%)

Special steel refers to steel with special chemical composition (alloying), produced by special technology, with special structure and performance, and able to meet special needs. Compared with ordinary steel, special steel has higher strength and toughness, physical properties, chemical properties and process properties. Such current products include: alloy structural steel, silicon steel, nickel-based alloys, tool steel, spring steel, bearing steel, weathering steel,heat-resistant steel...etc.

Stainless steel is the abbreviation of stainless and acid-resistant steel. Steels that are resistant to weak corrosive media such as air, steam, and water or have rust resistance are called stainless steels, and are resistant to corrosion by chemical corrosive media (acid, alkali, salt, etc.) it is called acid-resistant steel. Products under this category include: austenitic stainless steel, ferritic stainless,steel martensitic,stainless steel, duplex stainless,steel,precipitation hardening stainless steel, etc.