Does anyone know anything about errors where the coin split in half after struck at the mint

Where one side has a normal strike and the other side is blank because the coin split in half? Are these types very rare? This question is in regards to coins from the 20th Century but not moderns, maybe nothing newer than the 1950's.
Thank you
Thank you
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Comments
A true split planchet will always have a rough back surface. If you have something with s smooth, flat backside it was ground down outside the mint.
Three ways to break a coin