Kester^® OR-421 Flux Cored Wire

Kester® OR-421 Flux Cored Wire is a high-activity, water-soluble solder wire designed for reliable performance in electronics assembly and industrial soldering applications. Engineered with superior heat stability and enhanced wetting capabilities, OR-421 delivers consistent soldering results on copper, brass, nickel, and other challenging surfaces.

Compared to competitive flux-cored wires, Kester® OR-421 produces less odor during soldering and leaves near-neutral pH residues that are less corrosive, supporting improved reliability in solder joints. Classified as ORH1 per J-STD-004, this flux-cored wire can be applied with soldering irons, rework tools, or localized heating sources.

Its excellent thermal stability makes it compatible with high-temperature alloys such as Sn95Sb5, Sn63Pb37, and K100LD. Suitable for electronics where water cleaning is used and for mechanical assemblies such as refrigeration coils, heat exchangers, and tubing.