The 4 series aluminum coil sheet falls on aluminum series with silicon as the main alloying element, that is, aluminum-silicon alloy, represented by 4A01, other products include aluminum coil 4004 alloy, 4045 aluminum coil, 4047 aluminum coil, 4047 aluminum sheet, 4043 aluminum sheet etc. Usually the silicon content is between 4.5-6.0%, and the color is black-gray after anodizing, so it …