Hot sale DIN6923 hex flange nut, one-piece hex nut with integral serrated flange. The serrations under flange provide anti-loosing performance under vibration. Wider bearing surface distributes pressure and protects workpiece, no separate washer required. Made of carbon steel or stainless steel A2/A4. Widely used for machinery, vehicle, steel structure, construction brackets and electrical assembly. Sizes M4~M20. Zinc plated, black oxide or HDG available.