vintage goldtone pin bar

hi...just wanted to share a pic of this beautiful goldtone bar pin...I really like the texture and I wonder how they do this and what this technique is called...I noticed a round oval plaque on the back of the pin and I tried to photograph it but the writing is soooo darned small it just wouldn't photograph well for me...the plaque says 'americ' and has an arrow with what looks like 'kj'...I have no idea what this means and I am hoping someone may be able to help me out with some info...thank you for looking and I look forward to any comments or info about this awesum bar pin...can it be used as a tie bar? or is it just for ladies?