The 316 stainless parts cost retail a whopping R143.56! thats around U$17.48 right now?
The good side is I could find what I required and in one store, the threads on the larger bolts are very rare (today) UNC (unified course) and could be hard to find in many places ,Brasil comes to mind? That thread and its nuts and bolts are still used on engines like the British Seagull. You can use a Whitworth spanner on such bolts.
Dissimilar metals? I have used stainless with bronze in this application for many years and never had any bothers, I did not even bother to ask for bronze fittings, imagine the price!
I guess the bottom line is we can at least find such uncommon threads and off the shelf, the sales guy was so well trained that he did not even check the threads gauge, just the diameter, which will be Imperial and 9/16 of an inch, he knew by sight that the thread was UNC.
Shopping for your yacht when in Cape Town makes good sense!
The Unified Thread Standard (UTS) defines a standard thread form and series—along with allowances, tolerances, and designations—for screw threads commonly used in the United States and Canada. It has the same 60° profile as the ISO metric screw thread used in the rest of the world, but the characteristic dimensions of each UTS thread (outer diameter and pitch) were chosen as an inch fraction rather than a millimeter value. The UTS is currently controlled by ASME/ANSI in the United States
http://en.wikipedia.org/wiki/Unified_Thread_Standard My thanks to Wikipedia for supplying this information.