1.solder bar 2.lead free solder bars 3.used manual soldering ,wave soldering optional 4.8 ... , plumbing, and assembly of sheet metal parts. Manual soldering uses a soldering iron or soldering gun. ... 'hard soldering', 'silver soldering', or brazing.Lead-free solders in commercial use may contain tin, copper, silver ... much lower melting points are available manual soldering 8%Zn3% Bi Lead-free solder bar