I purchased 3 boxes for the summer bluegrass season.. when it was time to change from the D'Addario's the first box was rusty.. all of the strings. Second box was the same. third box ? Yep.. I wanted to send them back to the factory but they didn't want them either. Factory rep stated a bad batch of wire apparently got thru QC.. Scrapped the other two boxes. To be fair, the factory did replace them. With more rusty strings in the first box. Didn't open the other two. Friend of mine who touts these strings also had an issue with rust... there are other strings out there. Personally, I won't be buying them anymore.