What Causes A 100% Split Planchet?

Ok, Imagine this. This will be to describe the effect not to say that the metal in a strip of coinage material is made this way. This is just to describe the end result.

Imagine cookie dough that has been rolled out, now imagine folding it in half.

Now imagine a cookie cutter cutting the folded dough into the shape of a disk.

In this case, the disk would now have a layer of air in the middle of it. The dough may not hold together well along that "fault" between the layers.

For other reasons, such as badly mixed alloy, there can be air or impurities in the middle of a blank that then becomes a planchet and is then struck into a coin.

If a planchet such as what I described is struck into a coin, there is the possibility that the obverse can split from the reverse along the "fault" in the center of the planchet.

I hope that helps.

It's basic but it gives you the idea.

Thanks,
Bill

Hope you's don't mind if I show a couple of split plancets from Oz.
The first is both halves of a 20c piece.


The next is split about 90% of the way around, another 20 c piece.

Are this possible to fake? How do the grading companies know which ones are real and which ones are not?

A real fine diamond saw can do it . The key is to look for that look to the surface that is visible in the picture of the split planchet. It is usually striated and somewhat rough.