"Ok I guess when it was made conical washers didnt exist and they made them from nuts as they dont seem to be very symetrical.
Thanks a LOT for al the info and the effort to take the measurments!! I will let you know how it turned out :)"
"Thanks a lot!! finally I can try to build one of my holy grail lamps! one last question if you dont mind...are those conical washers at each end of the rods threaded and screwed to the rod or are they just sitting there without any thightening to…"