Click image to view full size image
Stainless steel clad copper cored rod protects copper from corrosion.It has excellent mechanical strength, ductility and greater reliability. Copper core permits simple electrical connections and greater conductivity which allows a smaller conductor than solid for the same power requirements.
link:https://www.ygmetal.com/clad-metals/stainless-steel-clad-copper/stainless-steel-clad-copper-cored-wire.html
Metal Glass Sealing Rod