Soldering, (pronounced sod-der-ing) is similar to welding. Soldering differs from welding as welding involves melting two metals together, where soldering is the melting of metal to attach it or something to something else. Soldering is a process of melting metal (called solder, but pronounced "sod-der") that can be composed of various types of metal (Tin, Lead, Copper, Silver, Antimony, Gold, Bismuth, Indium, Zinc). Soldering is performed on jewelry, plumbing (copper pipe), cabling or wires, and on electronics, mostly for connecting components on a (PCB) printed circuit board.
Soldering irons are the hand tools that generate the heat to melt the solder. Soldering irons are also known as soldering guns, soldering tools, soldering pencil, or soldering handpieces. Soldering irons can vary in shapes and sizes and generally can have their tips removed and replaced. Inexpensive and basic soldering irons have a power cord attached to the soldering iron for ease of use, but lack in the ability to make adjustments to temperature or power intensity.
Temperature is important as solder element content melts at different temperatures. For example, a very common solder is Sn63 Pb37. All the numbers must add up to 100, being 100%. The two letters in this example represent the element on the periodic table of elements. Sn being Tin and Pb being Lead. So a 63% Tin and 37% Lead solder melts at 361 ?F (183 ?C). Sn60Pb40 melts at 361?F - 374?F. Sn50Pb50 melts at 361?F - 419?F. The higher the tin concentration, the greater the tensile and shear strengths. Lead Free Solder, which is ROHS Compliant, generally melts in the range of 441?F.