1992 D 1c die clash and Rockwell test mark?

Discussion in 'Error Coins' started by Bargainbidder, Mar 2, 2021.

  1. Bargainbidder

    Bargainbidder Active Member

    I know its zinc but I was just reading about the Rockwell test mark and then I came across this. It probably is a blister or die chip but included in pics(pic 9)is what is believed to be one. What does everyone think?
    That and is die clash responsible for what is seen in each bay of memorial and on roof?
    Thanks again
     

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  3. cpm9ball

    cpm9ball CANNOT RE-MEMBER

    It looks like any other Crappy Zincoln to me.
     
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  4. Kentucky

    Kentucky Supporter! Supporter

    A Rockwell Hardness test is done on pure metals and alloys, why in heavens name would it be done on a plated object...uh, sorry @cpm9ball a Crappy Zincoln?
     
  5. cpm9ball

    cpm9ball CANNOT RE-MEMBER

    ROFLMAO 1.gif ROFLMAO 1.gif ROFLMAO 1.gif ROFLMAO 1.gif ROFLMAO 1.gif
     
  6. Bargainbidder

    Bargainbidder Active Member

    Not sure but example in pick was done on a 1971 Lincoln and is why I was asking. Article from Coneca stated John Devine verified. Article states testing was done before and after 1982.
     

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  7. Fred Weinberg

    Fred Weinberg Well-Known Member

    The OP's coin is not a Rockwell Test Piece,
    and although I knew John Devine very well,
    and thought highly of his numismatic expertise,
    I do not believe that 1971 cent is a Rockwell Test Piece.

    I saw the RT operation at the West Point Mint back
    around 2006 or so - and the 'ding' that is placed on
    the planchet is not that deep, and would disappear
    under 65-75 tons of striking pressure.
     
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  8. potty dollar 1878

    potty dollar 1878 CRH,my only indian and oldest coin found.

    Its just a normal pennie nothing special here.
     
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  9. Bargainbidder

    Bargainbidder Active Member

    Thank you for the information and being article said a person would have to be there as you have been answers my question. That and I couldn't find more as article indicated, but coin is in really bad condition and had to ask.
     
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  10. John Burgess

    John Burgess Well-Known Member

    comment removed as unnecessary by author. Me.
     
  11. Pete Apple

    Pete Apple Well-Known Member

    The John Divine mark has had its authenticity questioned by me in my paper on the CONECA site and by Mike Diamond. Even the test mark example in my paper has been questioned by Mike...he says microscopic pressure ridges are visible (which I cannot see). There is a debate as to whether a test mark can survive a strike. Mike and Fred are doubtful and the US Mint suspects it may be possible, so makes every effort to make sure that no test marked planchet enters the striking chamber.
     
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  12. Kevin Mader

    Kevin Mader Fellow Coin Enthusiast

    When I read about this (hardness test), it frankly didn't make sense to me having done hardness testing in a past life and being around stamping/coining operations for 30 years. The malleable nature of copper under that kind of tonnage essentially liquifies the outer layer of planchet. The likelihood of a penetrator mark surviving seems extremely unlikely. The folks at the mint might have personal experience with this that refutes thought, but on the coining operations I've been around...not a chance. I will check out your paper later. Thanks for the input/history.
     
  13. Fred Weinberg

    Fred Weinberg Well-Known Member

    At the WP Mint, they were doing it on Silver Eagle
    Planchets the day I was there, so it is used on
    varying metals, which makes sense.
     
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  14. Kevin Mader

    Kevin Mader Fellow Coin Enthusiast

    Here's the link to Pete's article: Rockwell Hardness Test Marks On Lincoln Cents | CONECA (conecaonline.org)

    I particularly appreciated the point on the 1995 cent (zinc substrate). The T scale makes sense to me relative to the thickness and softness of the material (it's what I would have done). I am surprised to read that there is some consensus that the penetrator mark would survive the minting process. That said, most coining I've seen done was being done on much larger equipment.

    Not something that I expected to learn today...but learn I did.
     
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