Activated Cored Wire Flux Formulations
CW-201 Standard Activated Rosin: CW-201 is a traditional RA-type flux as defined by the legacy Mil-Spec QQ-S-571. It uses traditional grade WW rosin and standard chloride activators. CW-201 is recommended for use with 63Sn/37Pb and 60Sn/40Pb alloys on nonsensitive oxidized copper parts, non-sensitive electrical/electronic assemblies where higher speed wetting is desired, assemblies where the residue is removed after soldering, and for soldering to moderately hard-to-solder metals such as brass and nickel.
CW-207 Activated Rosin for Lead-Free: CW-207 is similar to CW-201 except that it is formulated using a blend of heat-stable clear rosins. It is the standard option for soldering with lead-free alloy cored wire when soldering non-sensitive electrical or electronic applications, or when soldering moderately difficult-to-solder metals such as brass or nickel.
CW-209 Highly Activated Rosin: CW-209 is exactly the same as CW-207 except with twice the amount of halogen activator. It is recommended for use where CW-207 or CW-201 are not active enough to solder to highly oxidized metals, or where the speed of wetting is a high concern.