The scraper blade will not scrape off any type of coating or metal because it is the exact radius as the bolt tail. I dont know what process is used for the nickel boron coating or how resilient it would be to the scotch brite polishing pads. The polishing pads do remove the parkerizing found on most normal bolts, but still do not effect the actual metal of the bolt. If you are concerned about the nickel boron finish, you may want to ask the maker if it will come off with a scotch brite or you may consider my smaller tool (the scraper only version) that just gets off the majority of carbon but does not polish off every last bit. I have these available for $19.99 and again these scrapers do not cut into the metal of the bolt, they just scrape off what is on top.