Introduction
Sweden standard steel numbers are a system used to differentiate a variety of steels. The system was devised by the Swedish steelmaker ASSAB and is widely used in Europe and North America. The system assigns a four-digit number to each steel, which includes information about the grade, alloying elements, and some related characteristics.
History
The Swedish Standard Steel Number (SSN) system was first developed by the Svenska Jarnvarumassan (Swedish Iron Trade Association) in 1898. Initially, the system only consisted of letters, denoting the type of steel and its intended use. In 1949, ASSAB introduced the four-digit number system which is still in use today.
How It Works
The first two digits of the four-digit SSN denote the grade of the steel. For example, 00 denotes unalloyed carbon steel and 12 denotes a high-grade steel. The second two digits indicate the specific alloying elements. For example, 18 is chromium-manganese steel and 20 is chromium-molybdenum steel. Some SSN may also have a suffix letter, which denotes the specific form for the steel.
Grading
The first two digits of an SSN identifies the grade of the steel. For example, 00 denotes unalloyed carbon steel, 05 denotes a chromium-manganese steel, 12 is a high-quality carbon steel, and 52 is manganese-molybdenum steel. Higher numbers indicate greater alloying elements. The same grade of steel may have different SSN numbers based on its form or other characteristics.
Size Designation
The suffix letter, at the end of the SSN, denotes the size range or form of the steel. A letter appears at the end of the SSNs of bigger sized products, such as rods and plates, while smaller sizes such as strip steel do not have a suffix letter. Some of the common suffix letters are C for Cold Forming, H for Hot Forming, and P for Precision Forming.
Advantages of the System
The SSN system is advantageous for both buyers and sellers as it provides an unambiguous and universal identification for steels. This allows buyers to clearly communicate their steel requirements to sellers and vice-versa. The precise information provided by the SSN system also makes it easier for buyers to compare different types of steels and determine which ones best meet their needs.
Conclusion
The Swedish Standard Steel Number system is a convenient and universal classification system for identifying and comparing different steels. The SSN system is advantageous for buyers and sellers as it provides precise information that can be easily understood, which facilitates efficient and accurate communication.
