Indexa: FC03 M12 Knurled Nut FC03 - Knurled Nut Material: Medium Carbon Steel. Hardness: HRC 30 - 35. Surface Finish: Black Oxide. MPN: 5036140377899 EAN: 5036140377899 FC03 M12 Knurled Nut Attributes: B: 12mm MFR Part No.: PT03-1228 Material: Carbon Steel Surface Finish: Black Oxide Type: Knurled Nut