... ,10.9,12.9 4. Material: Q235,45#,40Cr ASTM DIN GB Rail high tensile nut bolts with large hexagon head ... . Item:High strength bolts for steel structuresII. Specification: DIN 6914, DIN 6916, DIN 7990, DIN 7999, DIN 931, ISO 7412, ISO 4775, ISO 7416, JIS ... .Our company (Suzhou Sudelan Railway Parts Co., Ltd.) is specializing in producing railway fasteners. We have certified by ISO9001:2008 Quality ...