... steel;brass etc.GradeDIN:4-12: SAE GR.A-GR.8FinishPlain;black;zinc plated(Cr,3+);zinc ... zinc, white blue zinc, and phosphatingGrade: 4.8 5.8 6.8 8.8 10.9 12.9Material: carbon steel, brass,stainless ... hex nut:4. Metric standard: Grade 4.8, Grade6.8, Grade8.8, Grade10.9,Grade12.9.5. Inch standard: ... 70, A4-807. Size: M3-M48 or as reqeust.8. OEM & Customize non-standard products welcome.9. Surface: ...