In the end. Saltwater and stress take their toll. After 20 years it's just time to retire metal and replace it with new.

Preferably beefier.

The chainpates we're replacing were 304 and 25 years old. If we went with 316 It would be good to beef them up with heavier to make up for the strength difference but why? Better to just replace them every 15 or 20 years of abuse.

Wait,,, I won't own the boat in 20 years.