I'm sure there is more to this than just metal fatigue. Type of cymbal, how hard and how you hit, the factors are numerous. I currently have a ride that is from the 30s, and a Zildjian Turkish K with a 67-77 stamp. Both are fine, minus the dirt.
I don't like arguing with physics either. There is lots of wiggle room with some things though, depending on variables.
I don't like arguing with physics either. There is lots of wiggle room with some things though, depending on variables.