Carbon steel is an alloy primarily composed of iron with carbon added, and its mechanical properties vary significantly depending on its carbon content. Low carbon steel offers excellent ductility and weldability, medium carbon steel provides a good balance of strength and toughness, and high carbon steel boasts high hardness and wear resistance. Because its strength and hardness can be freely adjusted through heat treatment, it is used in a wide range of applications. Representative processing methods include cutting, forging, rolling, pressing, and welding. It is an indispensable foundational material in diverse fields such as automotive parts, machine structural components, tools, and construction materials, owing to its excellent workability and cost performance.