nut bolt: 1Spec:DIN,JIS,ASTM,GB,UIC 2Surface:black 3Grade:8. ... :Q235,45#,4Cr Rail fastener high strength structural steel nut bolt I. Item:High strength bolts for steel structuresII. Specification: DIN ... from the Ministry of Railways, P.R.China. 2.From 2006, we have manufactured the products of high speed railway and ... Welcome your visit! Rail fastener high strength structural steel nut bolt