I am getting rust on many of the allen-head bolts on my bike (seatpost binder bolt, stem bolts, chainring bolts). Apparently, these things aren't made of stainless steel? But other parts of the same bolt are not rusting. Is there some coating put on the bolts that gets worn off from the allen wrench? I'm able to get the rust off with Brillo pads, but it always comes back after it gets wet.

Does anyone have any recommendations for this? It really ruins the otherwise beautiful apperarance of my bike. Any good sources of true stainless steel bolts? Or while I'm at it I guess I could get titanium.