What is the carbon percentage in 4130 alloy steel?

The correct answer regarding the carbon percentage in 4130 alloy steel is 0.30%. This classification refers specifically to a low-alloy steel that contains chromium and molybdenum, which are added to enhance its mechanical properties such as strength, toughness, and hardenability.

4130 steel’s composition typically indicates that it has a carbon content approximately around 0.30%. This level of carbon allows the steel to maintain good weldability, ductility, and strength. For applications such as manufacturing aviation components, automotive parts, and various structural applications, the balance of carbon with other alloying elements like chromium and molybdenum is essential.

Understanding the precise carbon content is crucial for engineers and designers when selecting materials for specific applications, as it directly affects properties like hardness and tensile strength, influencing performance under various conditions.