Hi All What should I use for boiler bushes? Gunmetal or Phosphor bronze and what grade? I have been told Phosphor bronze grade SA660 but as that is leaded and would it not cause problems when silver soldering? Andy MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.