1.5 gram 1956-D Lincoln wheat cent

Could one of you in the know tell me what planchette this 1956-D wheat cent was struck on . This coin has most of the border gone and is smaller  “18.1mm” than a regular cent. The weight of the coin is 1.50 grams and has a very weak strike on both sides. The coin is 0.6mm thick. Thanks, Coin Bum.   

I couldn't find any planchettes that would realistically match this, so my opinion is that the wear has managed to reduce its size and weight by that much, or it could be a counterfeit or something like that. 

Hi Coinbum.  That's called an acid coin.  It was dipped in acid or some other highly corrosive mixture:

"Acid Shrunk Coins"
http://www.error-ref.com/acid-shrunk-coins