A325/A490 steel structure bolt set from 1/2" to 1-1/2" This stud bolt set is used in steel structure engineering, bridge, high-biuilding etc. We can supply all the grades and finish treatment, the grades include10.9S and 12.9S etc. the finish treatment includes ZP/HDG/BLACK/PHOSPHATE/DACROMET/ FLUOROCARBON CERAMIC COATED etc. Now we export large quantity to USA, CANADA, GERMANY, MIDDLE EAST etc.