Serrated and without serrated under flange head , hexagon nut with internal threads , flange can enhance touching area to make nut not easy to loose and improve tightening torques . Which is good partner for bolt and machine screws . Internal threads tolerance is 6H , product quality from 4 grade to 10 grade , recommended materail choice for carbon steel and alloy steel , Specification : M10 Material : Carbon Steel Grade : 8 Finish : Yellow zinc Hardness : HV350 Proof Stree : 890N/mm square More data for flange nut , please see Technology |