50/50 solder is a 50% tin, 50% lead alloy. 50/50 Solder blend has a higher melting point than 60/40 solder, often utilized to create a base bead, as it prevents "bleed through" to the back side of your project. Note: 50/50 solder has a duller surface when set. 60/40 is then used to create the final bead.