Brazing filler metal

In brazing, only the filler metal melts, the base metal remains solid. The liquid filler flows into the joint and alloys with the surface of the base metal – that's called diffusion. It's important that the filler metal matches the respective base metal combination, otherwise the joint won't be tight or won't hold. Make sure the working temperature is high enough for the filler to flow cleanly, but not so high that the base metal is damaged. Keep the brazing time short once the filler has run through everywhere.