The hardness and practical specifications are spot on. The composition requirement seems like a forester or bureaucrat trying to play metallurgist
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If CT uses 4140, 5160 or 1060 for FSS, it does not meet the requirement compositionally, although any of them could conceivably meet the other requirements as well or better than something composed according to the specification!

If CT uses 4140, 5160 or 1060 for FSS, it does not meet the requirement compositionally, although any of them could conceivably meet the other requirements as well or better than something composed according to the specification!