Iron is an abundant metal on Earth, and due to its excellent strength, workability, and cost-effectiveness, it is one of the most fundamental materials in manufacturing. It is widely used not only as pure iron but also as steel (carbon steel, alloy steel, etc.) with carbon and other elements added. It is an indispensable material in all fields, including building structures, automobile parts, industrial machinery, home appliances, and infrastructure. Processing methods are diverse and include casting, where molten iron is poured into a mold; forging, where it is heated and hammered into shape; rolling, where it is extended with rollers; cutting, where it is shaved with a blade; welding, which joins components; heat treatment, which adjusts strength and hardness; and surface treatment, which enhances corrosion resistance and aesthetics. By combining these processing technologies, a wide variety of products are created.