Material Basics Aluminum Standards: A Guide to Global Aluminum Alloy Designation Systems 4 min read • Updated September 2026 Several systems of aluminum standards exist for identifying and designating aluminum alloys and for specifying their properties. Understanding these aluminum standards is essential for selecting, comparing, and cross-referencing alloys across different regions and industries. The Main International Aluminum Standards As with other metals, the most prominent aluminum standards include the European EN (Euronorm), the US SAE and ASTM, the Japanese JIS, and the international ISO systems. The BRIC countries also maintain their own standards: the Chinese GB and YB, the Indian IS, the Brazilian NBR, and the Russian GOST. Euronorm aluminum standards use four digits to identify wrought alloys and five digits to identify cast alloys. They are broadly the same as the ISO aluminum standards and the US numerical method of identification, in which a four-digit number provides the unique alloy designation. This approach aligns with the International Designation System issued by The Aluminum Association in the USA. The Aluminum Association (AA) system is specific to aluminum and serves as the basis for aluminum standards and designations worldwide. For example, the chemical composition limits specified in the Euronorm aluminum standards are identical to those registered with the Aluminum Association for the equivalent alloys. Table 1. Global Aluminum Standards Comparison Standard Region / Organization Primary Purpose Typical Prefix / Format Example AA Aluminum Association (USA) Aluminum alloy designation 4-digit designation 6061 ASTM ASTM International Material specifications and testing ASTM B221 ASTM B221 SAE SAE International Aerospace and automotive specifications SAE AMS AMS 4027 EN Europe (CEN) European alloy designation and specifications EN AW-6061 EN AW-6061 ISO International Organization for Standardization International standards ISO 209 ISO 209 JIS Japan Japanese Industrial Standards JIS H4040 JIS H4040 GB China Chinese National Standards GB/T GB/T 3190 YB China Metallurgical industry standards YB YB/T IS India Bureau of Indian Standards IS IS 737 GOST Russia National standards GOST GOST 4784 NBR Brazil Brazilian standards ABNT NBR NBR 6834 Understanding Aluminum Standard Prefixes and Suffixes A prefix is used to indicate the governing standard—AA for the Aluminum Association or EN AW for the European aluminum standards. Within the European system, the prefixes carry specific meanings: "AB" denotes ingots for remelting, "AC" denotes a cast product, "AM" denotes a cast master alloy, and "AW" denotes a wrought product, as in EN AW-1050. A suffix "A" indicates a national variation of the alloy, as in EN AW-6005A. The Aluminum Association (AA) Designation System In the AA aluminum alloy designations, four numeric digits are used. The first digit identifies the principal alloying constituent (or constituents). The second and third digits provide the specific alloy designation; this number has no inherent significance but is unique to each alloy. The fourth digit indicates whether the product is a casting (0) or an ingot (1 or 2). The Unified Numbering System (UNS) for Aluminum Alloys Another widely used classification system is the Unified Numbering System (UNS), which has the advantage of covering all metallic alloy systems. For aluminum alloys, the UNS is essentially an adaptation of the Aluminum Association designation system to fit the UNS format. A UNS number is created by taking the three digits to the left of the decimal point in the Aluminum Association system and adding the prefix "A9" (meaning aluminum alloys), followed by a digit that reflects any letter prefix in the alloy designation. For alloys with no letter prefix, the next digit after A9 is 0; for those with an A, the next digit is 1; for B, it is 2; and so on. For example, in the UNS system, 356.0 becomes A90356, A356.0 becomes A91356, and C356.0 becomes A93356.