Shorter answer: We don't know -- those are good questions!
Longer answer: It was 20 years ago, and we aren't exactly metallurgists. IIRC, at the time it was something to do with a variety of "surgical stainless" to focus on the best corrosion resistance combined with something that was somewhat machinable. At the time, I think we were comparing 304 (easier to machine, much worse corrosion resistance) vs. 316 (harder to machine, but much better corrosion resistance). I think looking at metals that we were able to source in partial lengths might have been a factor as well.
In hindsight, one might be able to find something with better properties in a more specialized alloy, but if I had to do it over again, I would 100% be willing to choose the 316L again. I have zero complaints with it, and the corrosion resistance it offers is superb. In 20 years, I've never polished my ring once, and it still has that mirror-finish quality (especially on the inside where it has never brushed concrete).
I rarely take the ring off (sometimes when juggling) -- I don't worry about it and leave it on even when using tools or scrambling up a rock ledge or carrying cinder blocks or whatever. Very occasionally it will get scratches (concrete is one of the few things that has left a mark from time to time), but they're never very severe scratches, and they buff out nice and naturally over time. I imagine that I would be much more concerned about a softer precious metal, and I'm glad I have a more durable ring instead.
Longer answer: It was 20 years ago, and we aren't exactly metallurgists. IIRC, at the time it was something to do with a variety of "surgical stainless" to focus on the best corrosion resistance combined with something that was somewhat machinable. At the time, I think we were comparing 304 (easier to machine, much worse corrosion resistance) vs. 316 (harder to machine, but much better corrosion resistance). I think looking at metals that we were able to source in partial lengths might have been a factor as well.
In hindsight, one might be able to find something with better properties in a more specialized alloy, but if I had to do it over again, I would 100% be willing to choose the 316L again. I have zero complaints with it, and the corrosion resistance it offers is superb. In 20 years, I've never polished my ring once, and it still has that mirror-finish quality (especially on the inside where it has never brushed concrete).
I rarely take the ring off (sometimes when juggling) -- I don't worry about it and leave it on even when using tools or scrambling up a rock ledge or carrying cinder blocks or whatever. Very occasionally it will get scratches (concrete is one of the few things that has left a mark from time to time), but they're never very severe scratches, and they buff out nice and naturally over time. I imagine that I would be much more concerned about a softer precious metal, and I'm glad I have a more durable ring instead.