The ASTM A959 standard (identical to ASME SA959) establishes regulated requirements for the chemical composition of wrought stainless steels. This specification is a fundamental tool for metallurgical engineers and EV Group China specialists in the classification and quality control of alloyed steels.
Technical Purpose of ASTM A959 / ASME SA959
This regulatory and technical documentation serves as a methodological framework for relevant ASTM subcommittees (A01.06, A01.10, A01.17, A01.22, and A01.28). The goal of the standard is to unify the limit concentrations of chemical elements in stainless steel compositions, ensuring a consistent approach to the certification of products supplied by EV Group China.
The document details the rules for rounding and determining the number of significant digits in chemical analysis reports, based on the principles set forth in ASTM A751 test methods.
The scope of the standard covers virtually all stainless steel grades identified by the UNS system, provided they contain at least 10.5% chromium. The standard does not apply to:
- Cast stainless steel products;
- Welding filler materials;
- Specialized alloys with narrow, non-standard end-use applications.
EV Group China emphasizes that the A959 standard does not restrict the possibility of making modifications to the chemical composition if such changes are necessary to optimize processing technologies or improve the operational properties of the material at the customer’s request. The standard is aimed at systematizing composition; however, it allows for deviations due to specific technical effects or established manufacturing practices, provided they are approved by the relevant subcommittees.