According to the different carbon content of carbon steel round steel, it can be divided into three types: low carbon steel, medium carbon steel, and high carbon steel. Among them, the carbon content of low-carbon steel is between 0.05% and 0.30%, which has good weldability, plasticity, and malleability; The carbon content of medium carbon steel is between 0.30% and 0.60%, which has certain strength, toughness, and wear resistance; The carbon content of high carbon steel ranges from 0.60% to 1.0%, and it has extremely high strength and hardness