ABSTRACT
Tin is a very good electrical conductor, but when applying tin to electrical contacts and other conductive parts it is recommended to take several precautions due to the specific physical properties of tin. These precautions are summarizes in the so-called “Tin Commandments”: Tin-coated contacts should be mechanically stable in the mated condition; and Tin-coated contacts can be used under dry circuit or low level conditions. Tin plating is not recommended for continuous service at high temperature. At elevated temperature, the performance of tin-coated electrical contacts is degraded by the aging effects due to a rapid increase in the diffusion rate of copper and tin. Tin plating is susceptible to a so-called fretting corrosion. However, protective lubrication is necessary when it is not possible to achieve a mechanical stability. Application of a thin liquid lubricant film protects the contact surfaces from detrimental effects of disturbance or fretting motions.
