Qualitek 6040 solder wire with nc601e rosin free no clean flux qualitek nc601 60 071 1 5 a flux cored solder wire made from an alloy consisting of 60 tin and 40 lead the nc601e flux is a colophony free no clean type that leaves virtually no post soldering residue for a visibly clean solder connection qualitek solder wire 6040 nc601e rosin free no clean flux 11 071mm 500g reel