[Douglas]

Ahoy Bill , Yes , there are engineering guide lines, as to the recommended "shoulder area", on the chainplates,,, around the toggle pin holes.

I guess you would first check the toggle pin hole clearance, on the toggles you plan to use.

Way back when , Bruce Bingham, wrote a book on ferro-cement sailboat construction, which had an illustrated table guide line, that you could apply to your application, suggesting the necessary "shoulder area" .

There are other books that contain these recommended guide lines, as well, maybe even a book written by Brion Toss !

Sorry , but my memory escapes me , but your question is a v good one, and does need to be considered when fabricating new chainplates or link plates.