I built some piers at the beach, and had some lefe over, They were 14" gal. 5/8" bolts i figured the length I needed then welded the head end to the other threaded end , had a long 5/8" bolt. Otherwise the thing would not have stayed together/ Pried apart. the bolt is inside a piece of 1" pipe with large washers on each end of the 2 X 4's. Have used it a lot and always have to add something. Its all trial and error..Used a Rossman draining tub under it works fine..