... at least it was for the ones on a ~30-footer. I was planning some bronze chainplates and figured it would be less strong (or need to be larger) than stainless. Skene's 8th Edition had a chart showing the various dimensions - they were the exact same for stainless as for bronze for wire sizes from 1/8" to 7/8" (the chart did not go beyond that size).

I have seen bronze bar stock at Atlas Metal, and I think maybe at Alaska Copper.

I've been hearing good things about titanium for chainplates, but have not really investigated.