Finally managed to get a steel material that looks halfway decent. had to use the metallic paint material to do it. It can be a little too "perfect", the textures avaiiable don't quite capture the look of older steel with a few nicks. The "scratched" texture just isn't it, and I have not found one in the wild that I like. But the tone and reflectivity I do like for steel that has been around for a while, no longer any polish on it, but retaining a sheen under the surface dirt and discoloration, and it looks good from a little more distance.. that's only a 1/2" nut. A lot of the "too perfect" comes from having sharply defined edges, where a real part has rounded when you zoom in on it. Supposedly regular Keyshot can do that, but KS for 3DS apparently cannot.