The "groves" on the edge of a dime are only there AFTER the coin is struck. They are made at the same instant the planchet is struck by the dies that produce the two sides. The groves are called reeds and they are on the surface of the collar die that encloses the planchet during the strike. The collar keeps the coin round - adds the edge design and insures an exact diameter all at one time.
Therefore just because there are no REEDS on the edge does not mean it was not supposed to be a dime!
Perhaps you need to know the steps used to make a coin today. In a nut shell here goes.
1. Metal ingots are rolled to metal sheet of a thickness based on the coin being produced. It is just slightly thicker than the final product. At this point there are often lines on the metal surface running the length of the sheet caused by the rollers. They are normally obliterated totally by the later steps.
2. Then the sheet of metal goes through a Blanking machine (like a big cookie cutter) that makes BLANKS. These are just slightly smaller in diameter than the finished coin. But the weight is correct. At this stage the blank has a sharp edge with marks from the cookie cutter. These new striations are usually removed by step 3. I am leaving some steps out but it is hardly possible for a blank made in step 2 to end up being struck.
3. The Blanks are now UPSET. This machine squeezes the edge of the coin causing the very edge of the blank to get slightly THICKER. Both faces of the blank become slightly concave. The reason is so that the final coin will be well struck at the edges. If you don't upset the blank you get weak outer legends. At this point the Blank has become a PLANCHET.
4. The planchets get a bath and go to the press.
5. The strike. There are two dies one for each face of the coin. One die is usually fixed (the anvil die) and the other is mounted in the traveling portion of the press (the hammer die). The names go back to the times when coins were actually struck with hammers on an anvil, but that is another story. The third die involved in a modern coin press is the collar die. The planchet is placed on top of the anvil die by mechanical fingers. Then the collar die rises up to keep the planchet in place. The hammer die is pressed onto the planchet. The force is so great that the planchet metal extrudes into every nook and cranny of the THREE dies. When the hammer die backs off, the collar drops and the fingers remove the coin.
That is a quick explaination of the process. Errors happen when things go wrong. The value of the error is a function of how often the error happens and how closely the inspectors check for that particular error.
If anything is not clear - please ask.
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Posted 07/31/2006 07:16 am
