The tin-plating process is used largely both in the electronics industry, for its excellent electrical conductivity, and in the food industry for its non-toxicity when in contact with food.
The treatment complies with Directive 2000/53 / EC; 2002/45 / EC; 2002/62 / EC; 2002/95 / EC and 2011/65 / EU (Rohs); 2004/96 / EC; 94/27 / EC; 2002/61 / EC; 2001/95 / EC; 2003/11 / EC; 2004/21 / EC; 2003/36 / EC; 2003/53 / EC; 2006/122 / EC; Regulation 1907/2006 (REACH).
The tinning treatments are of a white/gray color, which remains even after contact with moisture (compared to the silver that blackens) and are tested for resistance to salt spray up to 200/300h, with deposits with 20 microns thickness (remember that the tin melts at a temperature of +230°C and resists to -70°C).
The UNI ISO 2093 specifies requirements for electroplated coatings of tin on already mechanically worked metal objects, to protect them from corrosion and to facilitate the welding.
According to legislation NEMI, referring to applications in the electronics industry with critical weldability, deposits must be opaque tin (matt) with a grain = 0,001mm/0,005mm and Carbon = 0.005%/0.05%. For aluminum alloys, copper and steel (for example small heat sinks, pins, etc ..) there must be a pre-treatment of 0,002/0,003mm of nickel (possibly opaque) / + tinning 5um as described above.