I'll second what bronko said. Fastner heads rust, no doubt about it. Only way around it is stainless fastners, which I have seen done. If you don't like the silver shine of them... heat them up with a torch (get them like WHITE HOT) and quickly dunk them in a small can of break free, tri-flo or some other very light machine oil. It will give them a nice lustered blue finish. Hence the name "flame bluing". Works good on small gun parts too.... props to Larry Potterfield.