Center bolts with nut Reasonable Price with Excellent Quality&Finishing. Center bolts,Hex bolts,Center bolts with nut. Specification1) Grade:Ordinary standard 10. ... steel,(40CR)ASTM 5140 steel3) Finishing:Black Oxide, Zinc Plated, Phosphate, Electrophoresis,Dacromet,ect.4) Diameter& ... are able to conduct proccessing in accordance with customers' engineering drawings, samples, specifications or OEM ...