A four-digit numerical designation system is used to identify wrought aluminum and aluminum alloys. In addition to providing a detailed account of the temper designation system for aluminum and aluminum alloys, this article describes wrought and cast aluminum and aluminum alloy designations. It also tabulates the grade designations and compositions of wrought and cast aluminum and aluminum alloys. The article provides information on cross-referencing of aluminum wrought and ingot/cast products according to composition, per the Aluminum Association, Unified Numbering System (UNS) and International Organization for Standardization (ISO) standards.