... Black,zinc,hdg,oxide 4.iso rohs approve hex head bolt 1. Standard:DIN931/933, DIN558/601; DIN6914, DIN960 ... Alloy steel, stainless steel. 3. Grade of hex head bolt:Metric standard: Grade4.6, Grade 4.8, Grade5.6 ... 8"-2-1/2". 5. Length of hex head bolt:0-3000mm or 0-10. 6. Surface treatment:Plain ... phosphate black, DACRO, etc. 7. Packing of hex head bolt:General packing: 15-25Kg per Carbon or Bag, approx 36 ...