Our solder wire is made from 99% tin, 0.3% silver, and 0.7% copper. With a 2% rosin core our solder wire is lead-free and nontoxic. With good soldering ability in both electrical conductivity and thermal conductivity, and an evenly distributed rosin core, this wire is great for many uses including rc cars, guitar equipment, wire splicing, stained glass, or jewelry soldering. Compatible with most soldering irons and equipment, this solder wire has less slag and smoke and is both heat fatigue and oxidation resistant. Whether your goal is to repair household electrical circuits or electrical appliances and toys, this solder wire flows, well, heats evenly, and is easy to use, and is a must have tool for any DIY electrical project.