I did kill a question posted last night about whether our boats had or have 304 or 316 stainless.
Then I figured I might as well Google it myself instead of expecting someody else to. I withdrew the post because I didn't get very far in finding a good answer.
The 1986-era E38 owners manual just says "stainless rigging."
It is apparently pretty hard to tell he difference in the field. The test is for molybdenum, a "Moly test."
One chemical kit I found is $400. A real tester is $35,000--and most shops don't own one. The world is full of steel mixtures, misidentified materials, advertising copy and outright fibs as to types of stainless and their actual composition.
316, I always thought, had superior corrosion resistance. But how superior?
Like all of us I've had stainless that rusted a bit, or not at all, and I even have had stainless that was slightly magnetic.
We do have a metallurgist on the forum, maybe he can simplify or correct.
I'm having the new chainplate made out of 316. I asked the welder about titanium, and he said "yeah but stainless stretches a little."
How's that for science? So, at my layman's level, I just went with what is known to be standard or comfortable ortraditional.
Edmund Burke, the philosopher, argued against "progress" and for tradition, which he said was too often tossed aside. He was right about the French Revolution, which didn't turn out so well despite a shiny beginning. Burke pointed out that farmers stick to known farming practices, rather than radical newfangled production ideas, because although a crop may produce only mediocre results using the usual methods, an untested method may fail entirely--and everybody would starve to death.
I don't know that Edmund Burke is commonly used as an argument for 316 stainless. And in fact the guy was a reactionary jerk. But then, politics is strictly forbidden here, except in the case of stainless.