You will probably not be able to find a metric sized NyLoc nut at Home Depot or Lowes. I wouldnt trust a regular (non NyLoc) nut with threadlocker. If you had to, buy two of the regular style nuts and use one as a jamb nut, along with the Threadlock.
Better off trying a good hardware store, NAPA, or a dealer to get the proper metric NyLoc nut
--Steve (O.C.)