i simply cannot comprehend how you think a drawing can possibly, in any way, contradict the metallography of service failures.
no, i just have service failure analysis to go on - sorry about that.
i don't now, but i used to!
apparently you missed it when i referred to "coatings" above. apparently you missed it when i pointed you towards fabrication methodology above.
if you did metallography and understood fabrication technology, sure. but if you don't have the understanding of service failures, you can't differentiate between mistake and policy. a spring failing as a statistical anomaly, or because of physical damage that sets a fatigue initiator, is not a concern. a spring that is guaranteed to break because of deliberate cost cutting, i.e. one that is not heat treated, shot peened or properly coated, then that is. frod springs are not heat treated, peened and just cheaply painted. if you think you can argue against those facts, then you don't understand how you're completely out of your depth.