[crob241]

If there are no makers markings to use usually you can go by the color of the bars, black or brown are coarse and white and red are finer, Also you can just try them on a test piece of steel to see which ones are coarser then others. I have buffing compounds that are 25 years old and only use them on non critical items and have learned to only use supplies from Caswells or Brownells and not the local discount house.