Complete analysis of Kester Solder Wire prove that every batch conforms to the strictest quality control standards in the solder industry. Kester leaded and lead-free solid core solder wire meets IPC J-STD-006C. Kester solder wire purchased directly or through Kester stocking distributors will conform to these requirements. - The highest virgin metals are used to make Kester leaded and lead-free solid core wire. For soldering applications that require maximum reliability of solder joints, especially for surface mounted components, only solder of the highest purity is acceptable.