The grades of wrought aluminum and aluminum alloys for processing aluminum materials consist of chemical element symbols and percentages representing metal purity or alloy element content. In the brand number of industrial pure aluminum products, the number is only expressed to one decimal place, such as a199.0.
If the industrial pure aluminum product also contains a maximum amount of alloy elements not more than 0.1% (except copper, which is 0.2%), the chemical symbol of the alloy element shall also be marked after the figure, such as A199.0Cu, that is, industrial pure aluminum with 99.0% aluminum content and ≤ 0.2% copper content.
If some impurities in industrial pure aluminum are controlled and there are special uses, capital Latin letters indicating the use shall be added to the number indicating the purity, for example, the brand of electrical aluminum with purity of 99.5%al is A199.5E.
The grade of aluminum alloy consists of the basic element symbol Al and the chemical element symbol of alloy elements - the average percentage of alloy element content. If the alloy element content is greater than 1%, only the integer of the content shall be marked. For example, if the average magnesium content is about 3.0%, the brand of aluminum magnesium alloy is aimg3.
If the content of alloy elements is less than 1%, no number is required.For example, the brand of aluminum-magnesium-silicon alloy with the content of magnesium and silicon less than 1% respectively is AlMgSi. In order to distinguish their content relationship, a decimal number representing the average content can also be added to the chemical element of one of the alloy elements, such as AlMg0.5Si.