Re: Hydraulic fittings?
I don't use any aluminum fittings except on the drag car where every Oz counts. Steel (which will be plated) is the best way to go. Brass will fatigue crack from the vibration. All of the stuff that I work on like Class 6+ trucks, off-road equipment,etc. all use steel. In the case of corrosive fluids then stainless is the way to go, but cost is very high.
Steel JIC fittings are easily available and priced right. You can always coat them with a bit of anti-seize if you are worried about exterior corrosion.