It amazes me that I often see old date nails like this one in ties that are still in great shape while ties from the 50's seem to (often) be so rotted I can pull the nails out with my fingers. I have actually popped the nail's head off on some of the 1920 and early 30's series when trying to pull them out of the wood. Also, it is not uncommon to find a row of these older ties where the nails were bent over (as is this one) when originally installed because the wood was so hard.