12.9 bolt grades: 1.Spec:DIN,JIS,ASTM,GB ... HDG 3.Grade:4.8,8.8,10.9,12.9 4.Material:Q235,45#,40Cr ASTM DIN GB Standard ... High strength 12.9 bolt grades with large hexagon head for steel ... details and drawings of the products to our e-mail! V. Our strength on exporting: 1.Our company (Suzhou Sudelan ... visit! ASTM DIN GB Metric High strength hex head 12.9 bolt grades