BS EN 573-3-2019 Aluminium and aluminium alloys – Chemical composition and form of wrought products Part 3: Chemical composition and form of products.
6 Alloy designations
The numerical designation systems used in Teal sheets and European Standards for wrought aluminium alloys are identical. As specified in EN 573-1  the prefix EN AW- is added.
The alternative chemical symbol based alloy designation system shall be based on EN 573-2.
Both the numerical and the chemical symbol based designations are indicated in Tables 1 to 8.
The International numerical system is the preferred one. The chemical symbol based designations are
indicated for reference only.
7 Sequence of elements
Standard limits for alloying elements and impurities are expressed in the following sequence: silicon, iron, copper, manganese, magnesium, chromium, nickel, zinc, titanium, gallium, vanadium, remarks, other elements each, other elements total, aluminium.
Limits of additional specified elements are inserted in alphabetical order of their chemical symbols under ‘Remarks”.
8 Rounding rules for determination of compliance
In recording chemical analysis test results, the number representing the result for any element specified in this standard shall be expressed to the same number of decimal places as the corresponding number in this standard. For unalloyed aluminium, the aluminium content is derived as described in 5.2.
The following rounding rules shall be used for determination of compliance with this standard:
a) when the figure immediately after the last figure to be retained is less than 5, the last figure to be retained remains unchanged;
b) when the figure immediately after the last figure to be retained is greater than 5, or equal to 5 and followed by at least one figure other than zero, the last figure to be retained is increased by one;
c) when the figure immediately after the last figure to be retained is equal to 5 and followed by zeros only, the last figure to be retained remains unchanged if even and Is increased by one If odd.BS EN 573-3 pdf download.