I used a 3/8"x24 fine thread bolt about 1 1/2" long cut the head off of it and used a hacksaw to cut a slot in the top for a flat screw driver to fit so you can adjust the slack out of the gallon markers rod to hold them in place, then put in lathe and drilled a 1/4" hole about a 1/2" deep in the opposite end for the gallon marker rod to fit in. If you don't have access to a lathe you can drill the 1/4" hole in it with a drill press or hand drill