3 Tix Solder Tubes For Guns, Irons, Torches, & Soldering Machines. This is a new set of 3 tubes of Tix solder. Adheres to all ordinary solderable materials and works with a gun, iron, torch or soldering machine. It is the hardest soft solder on earth. Melts at 275 F (135 C) and has a holding power of 4,300 PSI. Stays white and does not tarnish. Each tube contains 20 sticks that each measure approximately 3" (76.2 mm) long.