Soft face is exactly what it says, it’s got soft rubber faces, basically just a shrunk down rubber mallet. Use it on things you don’t want to leave marks on.
Double peen is basically just a soft face except one side is like a hard epoxy like material. Harder than the rubber side, still softer than a metal head would be.
Same for Soft face & double peen.
Soft face is exactly what it says, it’s got soft rubber faces, basically just a shrunk down rubber mallet. Use it on things you don’t want to leave marks on.
Double peen is basically just a soft face except one side is like a hard epoxy like material. Harder than the rubber side, still softer than a metal head would be.