Lead-free Nickel-free Barrel Gun Alloy Process Lead-free Nickel-free Barrel Gun Alloy Process is the newest process first developed by HANLIN Company which is guide the stream in Environment Protection. It has black and bright tin –cobalt alloy environmental-friendly layers. The process can be widely used on various kinds of substances which close contact with human’s skin, such as button; zipper sliders, toys, lighting, jewelries and digital products and so on. The process is developed for solving the following problems: the common nickel free black plating layer is unstable, it’s easy to make a noise, and strong acidity, high cost of black nickel plating process. The composition of plating bath is simple, and no need of special experience when handle. It is a process which just need assay, not experience. I.Process Features The most distinctive characteristic of the process is 707 tin salt can plating excellent quality black. There is no 707 tin salt in make up agent, so you need to add tin salt when make up. There is no cyanide ion in plating bath, and no cyanide in layer. The content of Cobalt in the plating bath is low, plating layers is nonmagnetic, and it’s hard to make a noise. Zero radioactivity. The process meets the newest premium grade requirements of EU standard; The acceptable range of plating bath concentration is wide, Proportion is alright between Baume 13 and 18. It has no effect on blackening; 4.The viscosity of plating bath is low, metal content is low, cut the loss of taken out plating work，reduce the cost. 5. The plating bath is stable. PH is between 9.5 and 10.5, little change, tin-cobalt metal ions will not decompose and precipitate  6. High current efficiency, it take less time to plating, Barrel plate just need 8 minutes to 15 minutes. Especially when plating light black nickel, save half time of substrate layer white bronze plating, at the same time, it reduce the cost of white bronze by 50%;