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<p>[QUOTE=&quot;GDJMSP, post: 7480743, member: 112&quot;]The striations are the evidence.</p><p><br /></p><p><br /></p><p><br /></p><p>In most cases it does exactly that. But, if and when the blank cutter is getting a little dull and worn itself, it leaves behind more severe, deeper striations than normal, that are not fully smoothed by the process. It&#039;s the same kind of thing as severe pre-existing planchet marks not always being obliterated by the strike.</p><p><br /></p><p>&nbsp;</p><p><br /></p><p>That&#039;s just it, it doesn&#039;t just occur with Proof strikes. And the higher pressure on Proofs makes little to no difference in what happens to the edge of a smooth edge coin. You have to understand that during the strike, once the planchet metal touches the collar, it can&#039;t get pushed against the collar any harder or tighter than it already is. Once it touches the collar it stops dead in its tracks. That&#039;s because the additional pressure of a Proof strike is being relieved by the metal being forced into the recesses of the die - which is precisely the purpose of the extra pressure to begin with.</p><p><br /></p><p><br /></p><p><br /></p><p>It is seen on business strikes just as often as it is on Proofs. And not seen on every single one of either type. Also, all the planchets are the same, all cut by the same cutters. So striations are present on all planchets for both Proofs and business strikes. One thing that can make them more readily visible on Proofs is all the extra preparation that goes into Proofs. Just any lines or tiny flaws are more readily visible anywhere, everywhere on Proofs than they are on business strikes, they are more readily visible on the edge as well because of that extra preparation. </p><p><br /></p><p><br /></p><p><br /></p><p>That&#039;s explained above - once the metal touches the collar it stops, it can go no further and no more pressure can be exerted against it because the pressure against the collar is being relieved by the metal moving into the recesses of the die. </p><p><br /></p><p>You also have to understand that the collars used on smooth edge coins are polished smooth so the coins can be easily ejected. But the cutting edge of a blank cutter, its always rough and its sides are always covered with striations even when it&#039;s brand new. The very grinding that makes it sharp creates the striations. And those striations are on the edge of every cut planchet. But as I said above, as dullness and wear of the cutter become more severe it leaves behind deeper, more severe striations that are simply not obliterated during the rest of the minting process.[/QUOTE]</p><p><br /></p>

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