Our factory mainly produces fastening hexagon head firmware according to the standards from various countries, the involved standards: International GB, American system ANSI, German system DIN, British system BSW, Japanese system JIS, international standard ISO, and so on. The products specification is from M5 to M22, the grade of the products is from German system 4.8 to 10.9 or from American system grade 2 to grade 8. And the surface varieties: original, black, zincification, galvanizing, and corrosion resistance green paint and plating --Dacromet, etc.