When the aluminum content is not less than 99.00%, it is pure aluminum, and its grade is represented by the 1XXX series. The last two digits of the grade indicate the minimum aluminum percentage. When the minimum aluminum percentage is accurate to 0.01%, the last two digits of the grade are the two decimal places after the minimum aluminum percentage.
The second letter of the grade indicates the modification of the original pure aluminum. If the second letter is A, it means original pure aluminum; if it is other letters from B to Y (selected in alphabetical order according to international regulations), it means a modification of the original pure aluminum, which is different from the original pure aluminum. In comparison, its elemental content has slightly changed.
Aluminum alloy grades are represented by the 2XXX~8XXX series. The last two digits of the grade have no special meaning and are only used to distinguish different aluminum alloys in the same group. The second letter of the grade indicates the modification of the original alloy. If the second letter of the grade is A, it means the original alloy; if it is other letters from B to Y (selected in alphabetical order according to international regulations), it means the modified alloy of the original alloy.
