My chainplates are/were 1/4" x 1 1/2" x 12" or so with three 3/8" bolts to attach them to whatever they were anchored to below decks and 1/2" holes for the pins on deck
. Stuck with 1/4" because that's what the boat had come with originally and were plenty strong. Ordered 1 1/2" flat bar stock in 316 from a metal supplier, can't remember who, and they sheared them to length. The material wasn't all that expensive, around $200 IIRC. Del drilled the holes, rounded off the ends and polished them for me. I could have done the job myself with a cheap
drill press, cobalt bits, cutting oil
and a grinder but Del did a much nicer job of it than I could have done. I did cut the old chain plates shorter, drilled larger holes and used them for backup plates for the new CP"s.
Might have gone with Titanium if I could have found the material reasonably. Old plates lasted more than 40 years which is way longer than I'll be around to enjoy the new SS plates. Actually wanted to go with bronze but couldn't find manganese bronze except in round bar. Only flat bar stock with suitable specs. around was aluminum
bronze. Seemed to have all the strength, etc, of Manganese but couldn't find any information or opinions on its suitability for chain plates.
There is not a problem with galvanic corrosion
on the rigging
between dissimilar metal unless your boat spends most of its life under water
. Bronze turnbuckles have been and still are the best for rigging
screws. Have been used with stainless terminals and wire without issue.