high tensile nut bolts: 1. Spec.: DIN,JIS,ASTM,GB 2. Surface: black 3. ... ,12.9 4. Material: Q235,45#,40Cr ASTM DIN GB Rail high tensile nut bolts with large hexagon ... :High strength bolts for steel structuresII. Specification: DIN 6914, DIN 6916, DIN 7990, DIN 7999, DIN 931, ISO 7412, ISO 4775, ISO 7416 ... ! Factory view figures: Welcome your visit! ASTM DIN GB Metric rail hex head high tensile nut bolts