high strenth for steel structure, yellow zinc High strength bolts with large hex head for steel structures1.Property Grade: 8.8s or 10.9s2.Materials: Low carbon alloy steel3.Surface treatment; Zince plated( contain yellow zince plated, blue and white zinc plated), galvanized, HDG(Hot dip galvanized), Phosphate, black oxide.ect.4.Apply to standard: DIN, ISO,ANSI/ASMT,JIS,GB,NF,ectAll our products ...