A lead-free tin solder wire whose composition is 96% tin with the remainder mostly copper with some antimony and a trace of silver. Melts at 440°F. Acid core means it's pre-fluxed. Provided in a spool containing 1 lb. of Tin 96 soldering wire, 0.025" (0.64 mm) in diameter. The ideal solder for pewter, it is also used in soldering copper-based metals. Made in USA.