Product description：3A21 aluminum plate is an aluminum-manganese alloy. 3A21 aluminum sheet is the most widely used anti-rust aluminum material. Cold working method is often used to improve its mechanical properties; annealed state has high plasticity, and semi-cold work hardening has good plasticity. 3A21 aluminum plate has low plasticity, good corrosion resistance and good weldability during cold work hardening. 3A21 is mainly used for welding parts that require high plasticity and good weldability, such as aerospace, military equipment, tooling fixtures, making propellant storage tanks, welding structural cabin skins, end frames, brackets and other welding parts, and in corrosion Catheters that work in sexual media, etc.