Hello Mobstar,
It would help to know more about the location in which objects are found. Example, there would probably be a great difference between an object found in Europe (and/or certain parts of Europe or another part of the world) and the U.S.
That is, if it were found in the U.S. somewhere, it is likely that it is not an "ancient" object. If it were found in another part of the world, or even in the ocean (which, you have indicated it was not, I think), it would be possible for it to be very, very old. If, however, if found in the U.S. and made of iron, it is probably something which was made after settlement here by Europeans.
Figuring things out like this is how we are able to make better determinations as to what an object is or may be. So, if you could be a bit more specific on where it was found, that may help. Just a tip for future reference. Best regards.
JDSCOIN