1.solder bar 2.lead free solder bars 3.used manual soldering ,wave soldering optional 4.8%Zn 3%Bi 5. ... used in electronics, plumbing, and assembly of sheet metal parts. Manual soldering uses a soldering iron or soldering gun. Alloys that ... ,[10] though solders with much lower melting points are available manual soldering 8%Zn3% Bi Lead-free solder bar