If you drop one of your favorite steel planes and dent the sole, metal displaced from the dent will likely leave a raised ring around it that can scratch wood. Simply rub the surface with a fine honing stone to remove the raised area. Once done, you can ignore the remaining dent, oil the unplated surface, and put the plane back to work.
If you have dents in the metal-clad doors in your home, one answer is to use auto-body fillers to make the fix. Either the polyester resin or fiberglass paste fillers bond well with steel, and the repair can be made like on a car. But, because you can finish the door with acrylic-latex trim paint, not glossy auto body paint, you don’t need the skills of an auto body technician to get excellent results.