I've found lots of chains while metal detecting but nothing quite like this.
This apparatus appears to be made of a tin or aluminum alloy with the number "24" on the face of it. My wife thinks it probably went to a strong box and I should go back and look for the loot. In all serious, though, could this be a chain that secured railroad merchandise or bank items? I just don't have any clue and its really got my curiosity up. Let me know any thoughts....Thanks for looking!