Nickel-silver (or called “German-silver”) actually does not contain any silver; it is, in fact, of Cu-Ni-Zn alloy, with shimmering surface. Sometimes it is added little Pb. (1-2%) to obtain certain level of machinability. Nickel-silver has been applied to household supplies (ex: tableware) and industrial applications. When the content of Ni. exceeds 18%, the anti-corrosion of Nickel-silver begins to increase and make its endurance of stress-corrosion-cracking more superior than that of other bronze alloys. Adding nickel to silver can produce silver alloy that possesses higher hardness, wear-resistance, less burning-loss and finer grains than pure silver. The contact resistance appears to increase, too. Besides, because silver and nickel are not miscible, metallurgy is applied to the production (Ni. content 5%~40%). Silver-nickel can be used as electrical contact because it is more superior in electrical and thermal conductivity, extensibility, physical strength, machinability and contact resistance than those of pure silver. Nickel-silver is widely adopted in diverse applications, especially in the fields of crude, gas, mining exploitation and musical instruments manufacturing.