Our house is made from steel, steel posts, joists and bearers. Steel frames and steel cladding and roof. Mr Wolf can huff and puff as much as he likes.
While building I have tried everything on the market to write on steel when cutting. Sharpie pens – work for a short time but the steel trashes the tip all too quickly and useless if the steel is damp. Chinagraph (very soft) – too thick a line and melts if steel is hot from Australian sun or if grinding or welding. Graphite pencil – difficult to see and shouldn’t be used on roofing or cladding as it can promote rust and voids the BHP warranty.
The best thing for marking steel I have found is the Markal welders pencils. They come in silver and red depending on what you are marking, write fairly well on damp steel, are easy to see when welding or grinding, even when steel is red hot and don’t cause corrosion. Also, they are cheap as from Mr Amazon.