... of flatness, burr,dimensional precision(±0.025mm),material thickness,plating and so on.Especially, plating is the most important , we ... 1. The defferent raw material :Iron and iron ally(such as spcc,sus) ; copper and coppyer alloy(brass, phosphor bronze,Beryllium ... Copper,and German silve and so on ); Aluminium.2. Parts ...