... /roll 4.Sn-8Zn-3Bi , lead free type tin solder details :Shape&Tolerance:WireAppearance:Surface bright , no ... The first number always represents the tin content; the higher the tin content, the lower the melting point ... common lead-free solder contains 95 percent tin and 5 percent antimony but has a melting ... in radio, communication, meters, instruments and copper, tin and irons and etc.2) Residue is easy ...