In the diverse world of steel, 1215 iron is an environmentally friendly free-cutting steel, lead-free and free of harmful substances. Its chemical composition and mechanical properties have their own characteristics, and it is available in a variety of delivery states. It has advantages such as multiple shapes, high precision, material saving and time saving, and is often used for electroplating shafts and general parts. 1022 iron has a specific carbon content, and its physical, mechanical, and thermal properties vary. It has good machinability and is widely used in many fields. 1010 iron is low-carbon and has its place in machinery, construction, and automobile manufacturing. The manufacturing process includes steelmaking and rolling. 10B21 iron contains elements such as boron, has a variety of heat treatment processes, and has different mechanical and physical properties. It plays a role in many industrial fields and has many material advantages. 12L14 iron has excellent machinability, smooth cutting, and good electroplating properties. It is often used in precision instruments and automobile parts, but has low contact fatigue. 40Cr iron, SS 410 iron, and 65Mn iron also have their own unique properties and application areas. When choosing the right iron material, it is necessary to comprehensively consider factors such as structural importance, load conditions, connection methods, temperature environment, steel thickness, etc., while taking into account price, reputation and user evaluation, and determine the most suitable iron material according to different usage scenarios such as construction, machinery manufacturing, special environments, etc., so that steel materials can give full play to their effectiveness in various fields and meet diverse engineering and industrial needs.