Country Of Origin Specification Prefixes

Steel specifications are often prefixed with initials which usually indicate the country of origin.

AISI — Iron-based or ferrous alloys adhere to designations established by the American Iron and Steel Institute (AISI) and the Society of Automotive Engineers (SAE). Examples of AISI-SAE steels grades are 1018, 4140, 9610 and 52100.

AMS — Metals or alloys meet specific Aerospace Material Specification (AMS) guidelines established by the Society of Automotive Engineers (SAE).

ASTM / ASME — The American Society for Testing and Materials (ASTM) is a non-profit organisation that provides a forum for the development and publication of voluntary standards for materials, products, systems, and services. Most specifications from the American Society of Mechanical Engineers (ASME) are adopted from or very similar to ASTM specifications.

EN — European Norm or EuroNorm (EN) specifications have superseded several older, national designation systems such as BS, DIN, NS and SS.

JIS — Japanese Industrial Standards (JIS) specify the standards used for industrial activities in Japan. The standardization process is coordinated by the Japanese Industrial Standards Committee and published through the Japanese Standards Association.

UNS — Metals or alloys meet the compositional standards in the Unified Numbering System (UNS), which was established by the ASTM, SAE, and several metal trade associations and societies. UNS identifies metals and alloys with a letter and five numbers. For example, carbon and alloy steels are identified as Lnnnnn, where L is the letter nnnnn is the number.

Specialty / Other — This refers to other unlisted, specialized, and OEM-specific (e.g., GE, P&W, Boeing, etc.) or proprietary material specifications.