... .9,12.9 5.u bolt and nuts steel u bolt,bolt and nuts,u clamp Biggest u bolt manufacturer in ChinaWe can produce ... .0mm,3.0mm8)Thread :UNF / metric thread9)Material:mild steel,1035steel,1045steel,5140steel,40Cr10)Shape:round,round flat,half-round ,half-round flat ... one of the best and most recognized professions in U bolt productions enterprises that have more than 10-year manufacturing experience ...