MB6 brazing rods are the standard of the industry. Used where close fit-ups cannot otherwise be maintained and yet joint ductility is of prime importance. This MB15 rod allows for brazing silver, tungsten but requires the use of flux. - Stay-silv 6 is slightly more fluid and can be used where closer tolerances are available and is somewhat more ductile than Harris 0. These medium-range alloys are well suited where close fit-up cannot be maintained. These filler metals are somewhat more ductile than Harris 0 or Stay-Silv 2.