2A11 aluminum rod is the earliest type of hard aluminum used, commonly known as standard hard aluminum, with moderate strength and good plasticity in annealing, hard quenching, and hot states. It can be heat treated for strengthening and can be used in quenching and natural aging states. It has good spot welding weldability and tends to crack during gas welding and argon arc welding; Machinable in the quenched and aged state is still good, but not in the annealed state.