Soldering's a process in which two or more metal items are joined together by melting and flowing a filler metal into the joint, the filler metal having a relatively low melting point. Soft soldering's characterized by the melting point of the filler metal, which's below 400 °C (752 °F). The filler metal used in the process's called solder. Soldering's distinguished from brazing by use of a lower melting-temperature filler metal; it's distinguished from welding by the base metals not… (More on Soldering)