Popular but technically wrong name for silver-bearing brazing fillers, which melt around 600 to 800 °C and so count as brazing, not soldering. Shops use it for everything from 15 percent silver phosphorus-copper rod on copper refrigeration lines to 45 and 56 percent silver alloys on steel and stainless, and nickel-bearing grades on carbide. A true low-melting tin-silver solder also exists, so the name causes mix-ups at the parts counter.
Silver solder the carbide tip on with the 49 percent nickel-bearing rod and black flux, then let it cool slow.
Phosphorus-copper rod is for copper and brass only; on steel it forms brittle phosphides and the joint lets go.
Also heard as
- silver braze
- silver brazing alloy
- hard solder
Related terms
Brazing
Joining metals with a filler melting above 450 °C but below the base metals, drawn in by capillary action.
Soldering
Joining with a filler metal that melts below 450 °C, wetting the parts without melting them.
Joint clearance
The gap between mating parts in a brazed or soldered joint, which controls capillary flow and strength.
Flux
Material that shields molten metal from air and cleans oxides, as rod coating, wire core, granules or paste.