What is the best way to put flat ends on SHC screws? There are no non-marring versions, only in set screws. Can I just grind a flat end and polish or is this a lathe or mill job? I built a steel armature that uses SHC screws to clamp the bars, but the SHC screws leave ugly marks on the steel bars. I bought non marring set screws for my boring head so the boring bars don't get marked. Not available for cap head screws, unless someone knows a source.