Review on AUSTOR 6 Pack 60-40 Rosin Core Solder Wire – Tin Lead Electrical Soldering Tools, 0.8mm Diameter, 20g by Justin Butler

This cheap Chinese solder will destroy the soldering iron tip and leave behind black spots on the solder joints. Adhesion is bad. It is too thin for general use - 0.6 mm is not enough; Use 0.031 inch (0.75mm) solder for best results when soldering small to medium sized joints and 0.5mm for surface mount. But stay away from cheap Chinese stuff and buy well-known brands. Even if the quality costs more, it's worth it.