3439-00-063-0987 (SN40WS0.1251LB)
3439-00-063-0987 is equivalent to manufacture part number QQ-S-571. It is a lead alloy solder and is classified under Federal Supply Class 3439 (3439 - Welding, Soldering, and Brazing Supplies and Accessories), stocked for defense, aerospace, MRO, and industrial maintenance applications. This item is cataloged in the NATO supply system under 3439 - Welding, Soldering, and Brazing Supplies and Accessories and is available through NSN-PARTS for U.S. government MRO, and commercial procurement.