... , etc. Business kinds: 1, carbon steel categories: 8.8 level, 10.9 level and 12.9 grade fasteners, import steel fasteners, pressure riveting ... cr3 + passivating galvanized 7, nickel, chromium plating, electrophoresis 8 9 10, black wardak gongs (zinc chrome plating coating) 11, 12, 13 ...