They remind me of 'waffle coins'.
'In mid-2003, the US Mint acquired machines to eliminate security concerns and the cost associated with providing Mint police escorts to private vendors for the melting of scrap, substandard struck coins, planchets and blanks. The Mint has not objected to these pieces trading in the open market because they are not considered coins with legal tender status."
Don.....
Source: The Official Red Book.