Basic definition and classification of carbon steel
Carbon steel is an iron-carbon alloy with a carbon content between 0.02% and 2%, and is one of the most common metal materials. According to different classification criteria, carbon steel can be divided into many types:
Classification by use：
 Carbon structural steel: mainly used in Bridges, ships, building components, machine parts and so on.
Carbon tool steel: mainly used for tools, molds, measuring tools and so on.
Free cutting structural steel: specially designed steel for easy cutting
Classification by carbon content
Low carbon steel (C≤0.25%) : soft, stamping and malleable, often used in the manufacture of chains, rivets, bolts, etc.
Medium carbon steel (0.3%~0.6%) : nature between high carbon steel and low carbon steel, mainly used in the manufacture of all kinds of mechanical parts.
High carbon steel (0.6%~2%) : hard and brittle, mainly used for general bearings, tools, etc