Message:

<p>[QUOTE=&quot;GDJMSP, post: 3046077, member: 112&quot;]The surface of raw coin strip, before the blanks are ever punched out, usually looks similar to these pics of yours - all rough and beat up looking.</p><p><br /></p><p><img src="https://www.cointalk.com/attachments/0404181858_hdr-jpg.760534/" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p><br /></p><p><br /></p><p><img src="https://www.cointalk.com/attachments/0404181908_hdr-jpg.760543/" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p>A lot of folks may not realize it but the polishing of dies is a multi-stage process. It starts out with a course diamond dust paste, and progresses in multiple steps with each successive step using a finer grit paste. Each of the early steps leaves the die polish lines on the die, with them becoming closer and closer together, and shallower and shallower with each step of the finer paste. Until finally all traces of the die polish lines are gone. It works the same way as it would for you if you were using different grits of sandpaper to sand something down. You start with course and finish up with very fine.</p><p><br /></p><p>With blanks, most are not polished at all. But when they are, whether for Proofs or the small dollar business strikes, the same kind of process occurs, but without the final polishing steps that dies receive. They don&#039;t care if the planchets have lines on them because most if not all of them will be obliterated when the coin is struck. That&#039;s why you can see the lines on the planchets. As I said above &quot;burnished&quot; is nothing more than a fancy word for polishing. If it were not for the polishing those lines you see would not even exist.</p><p><br /></p><p><br /></p><p><br /></p><p>The coin strip for silver, gold, and nickels is rolled out of an alloy, a complete alloy. No other layers of metal are added. </p><p><br /></p><p>The strip for clad coins, all kinds of clad coins, is layered. And that layer of metal you&#039;re referring to, that is done long before the blanks are punched out. And there is no polishing of the strip - none. The strip is produced and the blanks are punched out by the company who makes them. Then they are shipped to the mint. Again with no polishing having been done.</p><p><br /></p><p>As should be expected the surface of the strip, even in its final stage before the blanks are punched out, is rough when viewed under magnification. As the blanks are punched out they come off a roller belt. At various points along the way with washing and moving them from place to place all the blanks are all jumbled together, banging against each other and creating contact marks just like those that occur on coins after they are struck. That adds to the rough surface you see in those pics of yours.</p><p><br /></p><p>If there is any polishing done it is done by the mint, and it occurs to the blanks, before they go through the upset mill for that is the only way they can be polished. Once they are upset they can&#039;t be polished any more because of the raised edges - they have to be polished when they are flat.</p><p><br /></p><p>So before the planchets are ever annealed all of this is done and over with.[/QUOTE]</p><p><br /></p>

Your name or email address:

Do you already have an account?

• No, create an account now.
• Yes, my password is:
• Forgot your password?

Stay logged in