An ancient Chinese iron sword with a bronze handle. This kind of weapon refers to the Qin dynasty of imperial China that improved its strong military. The military used the most advanced weaponry of the time. It was first used mostly in bronze form, but by the 3rd century BC, kingdoms such as Chu and Qin were using iron or steel swords. Iron Age in the context of China is sometimes used for the transitional period of circa 900 to 100 BC during which ferrous metallurgy was present even if not dominant. Ancient Asian Weapons And Iron Age Collectibles.