... ,copper,brass 2)Heat Treatmment;Quenching,Tempering,Annealing Close die forging,Hot Forging,die forging Forged,Forged ... Ring,Hot Forging,Close Die Forging 1) Material: Carbon steel, alloy steel ... Normalizing ,Annealing, Solution, Passivation4) Production machine: Hot die forging presses,Friction press machine,Middle Frequency electric heater, Air hammer,Precision ...