To join or fuse with solder

ETYM Formerly soder; French soudure, Old Fren. soudeure, from Old Fren. and French souder to solder, Latin solidare to fasten, to make solid. Related to Solid, Sawder.
An alloy (usually of lead and tin) used when melted to join two metal surfaces.
Any of various alloys used when melted for joining metals such as copper, its common alloys (brass and bronze), and tin-plated steel, as used for making food cans.
Soft solders (usually alloys of tin and lead, sometimes with added antimony) melt at low temperatures (about 200şC/392şF), and are widely used in the electrical industry for joining copper wires. Hard (or brazing) solders, such as silver solder (an alloy of copper, silver, and zinc), melt at much higher temperatures and form a much stronger joint.
A necessary preliminary to making any solder joint is thorough cleaning of the surfaces of the metal to be joined (to remove oxide) and the use of a flux (to prevent the heat applied to melt the solder from reoxidizing the metal).