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<p>[QUOTE=&quot;RonSanderson, post: 5010728, member: 77413&quot;]The voids between the dies are designed to be filled with a volume of metal that exactly equals the volume of a planchet. If you add in some grease, now you have too much stuff to fit. The striking is trying to force too much material into a fixed volume. That should exert extra pressure throughout both the grease and the metal.</p><p><br /></p><p>Since the “grease” blob is probably not very compressible, the flow of metal into that void stops when its pressure is equalized by the pressure pushing back from the compressing grease. I would imagine this would create a new surface that is flat. Very likely, this does a good job of smoothing out planchet marks because of the higher than usual pressure. I would also expect other areas of the coin to be unusually well struck because of the extra pressure forcing the metal into every nook and cranny.</p><p><br /></p><p>I, too, am not sure what a flat strike is, but I will guess. Let’s take a planchet, like this one.</p><p><br /></p><p>[ATTACH=full]1201802[/ATTACH]</p><p><br /></p><p>It is fairly beaten up. The tumbling with other planchets leaves a dense pattern of small dings. If the dies are a little far apart, there will be more room in the die chamber than there is metal in the planchet. Where the dies come fully into contact with the planchet they can push the metal and eradicate most or all of the random dings.</p><p><br /></p><p>However, if you have a large void in the die, such as the Indian’s head or the buffalo’s shoulder, then too little metal will be pushed from the rim area up into the big void. The result is that much of the surface of the planchet will be untouched, and, well, flat. The surface of the coin in that area should still look just like the planchet we see above.[/QUOTE]</p><p><br /></p>

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