No offense, but what kind of engineer are you? Threaded brass inserts coupled with steel pins have been used for well over 100 years! Brass makes an excellent nut of any sort due to its' natural lubricity, hardness (soft!), and corrosion resistance.
As Chris posted earlier, it is a terrible idea to have two metals of the same kind used for the male and female sides of a threaded joint. They will be very likely to seize, sometimes permanently.
BTW, what was the earliest metal used for nautical applications, and why?