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Steel Numbering System
When working with steel, its important to understand the different components and types of steel that are commonly used around the world. One key way of quickly identifying different types of steel, particularly across international borders, is to know the various steel numbering systems that have been developed.
AISI / SAE Steel Designation System
The American Iron and Steel Institute and the Society of Automotive Engineers (SAE) have developed their own steel numbering system, known as the AISI/SAE steel designations. This system is comprised of a four-digit number, where the first two digits are the major alloying elements and the remaining two digits indicate the percentage of carbon.
For example, 1020 steel is a low-carbon steel that contains 0.20% of carbon. The first two digits identify the major alloying elements of the steel, which in this case are carbon, manganese, and silicon. The remaining two digits show the concentration of those elements.
BSEN / BS 970 Steel Numbering System
The BSEN/BS970 steel numbering system, also known as the British Standard steel numbering system, was developed by the United Kingdom and is now used in the European Union. Unlike the AISI/SAE system, the British Standard system assigns each steel grade a unique identification number. This system is comprised of three components: the steel’s indication number, supplier’s indication number, and an indication letter.
The indication letter assigned to a steel is based on its properties. For example, EN8D is a steel grade with a ‘D’ indication letter. This letter shows that it is a free-cutting steel that contains 0.35-0.45% carbon and 0.60-0.90% manganese.
JIS Steel Numbering System
The Japanese Industrial Standard (JIS) steel numbering system was developed by the Japanese Industrial Standards Committee and is used throughout Japan and the world. This system is comprised of four parts: the steel type, the standard number, the grade, and the chemical composition.
For example, SS490 is a steel grade with a standard number of JIS G3101. This grade contains 0.25% of carbon, 0.050% of sulfur and phosphorus, and 1.05-1.70% of manganese.
Other Steel Numbering System
Other commonly used steel numbering systems include the ASTM steel designations, the Chinese steel numbering system, and the Olympia steel numbering system. The ASTM steel designations are used to classify steels based on their physical and mechanical properties, while the Chinese Steel Numbering system categorizes steel grades according to their specific chemical composition. The Olympia steel numbering system is commonly used in the metal industry due to its simplicity.
Conclusion
The various steel numbering systems are extremely important when working with steel. Knowing the different components and types of steel as well as the various steel numbering systems helps to quickly identify different types of steel across geographical boundaries. This makes it easier to ensure that the right type of steel is used for a given project, which can save both time and money.
