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 Replies: 37 / Views: 4,176 |
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Moderator
 United States
56855 Posts |
The divot in the link is oblong the OP's is round. Does the Rockwell test leave a round or oblong divot? John1  |
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Pillar of the Community
United States
2376 Posts |
John1 , on an unstruck planchet a Rockwell test mark would be circular but when struck that circle would be distorted in accordance with how the coin metal flowed to fill the die. The OP's coin to me seems to have a divot that is wider than it is tall which seems correct because coin metal would flow to the columns to fill those voids in the die
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Pillar of the Community
 United States
3330 Posts |
stoneman227 and all...I really appreciate your help and the detail of the observations and the links. Isn't this forum and Community a great place?
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Pillar of the Community
United States
1414 Posts |
Pete, this is a super nice place! I learn something new everyday and I have been collecting since I was 14.
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Moderator
United States
56855 Posts |
Thanks stoneman227 that make sense. John1 |
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Pillar of the Community
United States
6478 Posts |
Never heard of the Rockwell test before. Learned something new!
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Pillar of the Community
United States
4809 Posts |
My experience with Rockwell testing suggests that if this is from a ball tip it happened before coining. I think if it happened after there would be more significant bulging around the rim of the mark. But I also think that the mark would be larger given the zinc substrate. My reference however dates back to testing aluminum decades ago and may not be as useful here.
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Pillar of the Community
United States
3330 Posts |
Quote:
My experience with Rockwell testing suggests that if this is from a ball tip it happened before coining. My understanding is precisely what you say here. It applies to a planchet test. (See the link quoted in OP). |
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Pillar of the Community
United States
5964 Posts |
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mark would be larger given the zinc substrate I would think they use different pressures on different coins. I also think there should be no ridge. |
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Bedrock of the Community
United States
17884 Posts |
It is clearly not a Rockwell test on the planchet. While you might test a planchet to see if the annealing was successful, you most likely would discard that planchet and not use it. If you did use it, the force of the strike would wipe out the test mark either completely or almost so. That clearly isn't the case here. So could it be a Rockwell test on a finished coin? Why would you do such a test? No almost certainly this is just PSD. |
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Valued Member
United States
449 Posts |
If anyone is curious there are other types of harness tests:
1. Rockwell (as many of you have listed)
2. Brinell
3. Vickers
4. Knoop
5. Shore
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Pillar of the Community
United States
3330 Posts |
Quote:
you most likely would discard that planchet and not use it. You are in agreement with the source I cited: Quote:
Such planchets are supposed to be discarded. This is the reason that coins with this test mark have a rather high rarity rating. However, the same source disagrees with your statement: Quote:
If you did use it, the force of the strike would wipe out the test mark either completely or almost so. It states: Quote:
If a planchet with a Rockwell test mark is struck by coinage dies, the pit is not erased. The pit's originally circular outline may, however, be distorted into a slight oval as the coin expands beneath the impact of the dies. The link is here: http://www.error-ref.com/?s=rockwellEdited by Pete2226
07/15/2015 1:25 pm
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Rest in Peace
United States
7075 Posts |
I think this is going to be tough to prove either way.
The biggest problem is that the coin is circulated. If if was fresh out of a mint roll then you'd know it happened at the mint and it doesn't look like a typical bag mark.
But since the coin has been circulated ... it could have happened anywhere.
All I can suggest is to keep searching for coins with test marks on the bay and the error coin sites, etc. Maybe there's more to be learned or an exact match.
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Pillar of the Community
United States
3330 Posts |
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All I can suggest is to keep searching for coins with test marks on the bay and the error coin sites, etc I have - it seems that there are very few. Doesn't mean I will not keep trying! Quote:
Maybe there's more to be learned or an exact match. I am sure that there is more to be learned (always is)! An exact match is highly doubtful because of the randomness of where the test is done on a planchet. |
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Rest in Peace
United States
7075 Posts |
It would probably help if you could get measurements (diameter and volume) and find a known test error with no distortion and compare the measurements -- but jeepers...it's so tiny!
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Replies: 37 / Views: 4,176 |
First Page
Posted 07/14/2015 07:53 am
