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 Replies: 8 / Views: 2,384 |
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Valued Member
Canada
219 Posts |
Did not get any acknowledgement from publishers  ... Is something wrong? A Rare Look at Punch Break Error By D.Lavoie It is fairly common to see a die break/chip error on coins but observing an error from a damaged punch is somewhat exceptional. The 2012 Canadian nickel offers us a rare occasion to view a punch break error. Working punches are heat treated, quenched, followed by tempering to increase the hardness of the metal. This process increases the resistance to plastic deformation but at the same time makes the metal very brittle and susceptible to break during use. Since a working punch only produces a small quantity of working dies, it will usually remain undamaged during the die manufacturing process. Those punches that do break occur at the weakest point, normally the small details forming the letters or numbers of a coin. When this happens, the punch will produce working dies all having an imprint of the break. In turn, the coins produced by these working dies, will all have the identical error representing the punch break. At first glance, a punch break can easily be identified as post mint damage. But in the case of 2012 Canadian nickel, working dies were produced with the broken piece of metal still attached to the punch. Three such working dies can be observed with part of the letter K of the initial K.G still attached as shown in Figure 2. A majority of the working dies were produced after the broken piece fell off, having part of the K missing as shown in Figure 3. The damage to the punch occurred early in the production of working dies due to the small population of coins having an undamaged K as shown in Figure 1. So, when several coins have identical post mint damage, further investigation may lead to a punch break error as demonstrated with 2012 Canadian nickel. Figure 1  Figure 2  Figure 3  |
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Valued Member
United States
214 Posts |
Very interesting. I never thought of this before. Thanks for teaching me something new!
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Pillar of the Community
United States
4963 Posts |
Very interesting! I just looked through the Canadian nickels I have found roll hunting here in the states and found a 2012, and sure enough, the K is broken like in figure 3.
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Pillar of the Community
 Canada
5589 Posts |
When you speak of the punch, are you talking about the "hub" which is the punch that impresses/makes the working dies? Or were the engraver's initials put into the already-made working die with a separate punch? Lots and lots of these occurred during making the Vicky large cent working dies.
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Valued Member
 Canada
219 Posts |
Quote:
okiecoiner
When you speak of the punch, are you talking about the "hub" which is the punch that impresses/makes the working dies? Or were the engraver's initials put into the already-made working die with a separate punch? Lots and lots of these occurred during making the Vicky large cent working dies. You are right and I too was using the term "hub" but I was told on this site, "punch" was preferred over "hub". Here is an excerpt that explains the differences between hub and punch. I have bolded part of the answer to show that some people prefers punch over hub. Quote:
Coin Clinic 2: 1,001 More Frequently Asked Questions
By Alan Herbert
Q:When referring to the tools used to make dies, do "punch" and "hub" mean the same thing?
A hub is a tool with the design in relief, or "positive," just as it will appear on the coin used to "sink" a die, which in turn has the design incuse or "negative." A punch usually is referred to as a tool used to sink a portion of the design, such as a letter, number or star into a die, but some mints use it to refer to the fully completed hub. Edited by numidan
05/17/2016 1:11 pm
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Valued Member
Canada
284 Posts |
Interesting to see the progression. Did you look at a large number of coins to find that progression? If so, is it large enough to give an idea of the percentage of coins found at each stage?
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Valued Member
Canada
219 Posts |
Since the first find in 2012, I've been putting them aside not knowing there were differences between them. Until now, I only found 7x special Ks, lucky for me some were different. It is only fairly recent that I was able to explain what had happened. Since the release of the article, someone has shown me a different variety of the ones shown above. Who knows, there might be more!
I can only hypotheses on the population:
202,944,000 nickels were minted in 2012 and I read a die can produce as little as 100,000 coins up to the excess of 1,000,000 coins. So if there was one die per progression, this means that people should find a special K in every 200x 2012 nickels. I will add that this may also be true for the undamaged K.
Edited by numidan
05/18/2016 10:14 am
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Valued Member
Canada
284 Posts |
By your numbers, it should be a special K for every 200 to 2000 2012 nickels. Too bad they don't come in the cereal box :P
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Pillar of the Community
Canada
3234 Posts |
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interesting to see the progression. ..and nice work in explaining it so well.. |
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Replies: 8 / Views: 2,384 |
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Posted 05/16/2016 10:49 pm
