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What's the cause of these marks on a Shield nickel.

Insider2Insider2 Posts: 14,452 ✭✭✭✭✭
edited July 19, 2017 10:33AM in U.S. Coin Forum

I posted this on the "Ask a Stupid Question Thread." I guess it was not "stupid enough." So, I'm calling all nickel and minting experts to chime in with an opinion. I have one based on something I was told long ago (will post it later) but I wish to read your opinions.

Insider2 Posts: 1,424 ✭✭✭✭

In The complete Guide to Shield and Liberty Head Nickels, this characteristic (the spikes from the "5") is said to be caused by "die erosion." When a die eroded, it makes sense that it should be in a "radial" direction from the center. In this image, that seems to be the case.

Stupid questions:
1.Should the erosion be wider on the field toward to recess of the die or should it start narrow in the field and get wider toward the recess (as in this case)?
2.Should die erosion "present" as sharp spikes?
3.Anyone have better images of this characteristic on a Shield nickel?
4.Is it possible there are actually two causes for these spikes with one being erosion and the other be tooling?"

 Quote ·  Disagree  Agree  Like  LOL

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Comments

  • yosclimberyosclimber Posts: 4,572 ✭✭✭✭✭
    edited July 19, 2017 10:58AM

    Could be a die clash, since the lines seem to be uniformly spaced?

    shieldnickels.net/clashOverlays/clashOverlays.html

    Howard did answer your question on the other thread:
    https://forums.collectors.com/discussion/comment/11757491#Comment_11757491

    @howards said:

    @Insider2 said:

    Question: what did you call the spikes into the field from the letters of Shield nickels and what did you think caused them. I forgot. Thanks.

    I call them "die fatigue spikes." They always occur along the edges of a coin device and protrude into the fields. My explanation (for which I have no proof) is that where the recess in the die for the device meets the field experiences extra stress, and is a likely spot for die failure.

    On shield nickels one often sees these along the edges of the big 5 on the reverse.

  • BillJonesBillJones Posts: 33,427 ✭✭✭✭✭

    I think these are reflections of little flakes of steel that chipped off the die during the minting process. The copper-nickel alloy that was used for the Shield Nickel was super hard for the times, and ate up dies like crazy. The most often noticed indicator of die deterioration is die breaks, but smaller, less noticed defects like this are a logical result.

    Think of it this way. When the coin is struck the metal flow goes into the recess, and given the hardness of the copper-nickel alloy, flakes of steel separated from the die in the process. This would not happen as often with silver and copper coinage, but it not unprecedented for those coinage metals.

    Retired dealer and avid collector of U.S. type coins, 19th century presidential campaign medalets and selected medals. In recent years I have been working on a set of British coins - at least one coin from each king or queen who issued pieces that are collectible. I am also collecting at least one coin for each Roman emperor from Julius Caesar to ... ?
  • CaptHenwayCaptHenway Posts: 31,499 ✭✭✭✭✭

    I am familiar with these irregular horizontal lines on Shield nickels, and they are not die erosion lines, which tend to be both radial and near the borders. They do not look like clash marks because they are too irregular, but I do not know what caused them. Perhaps the result of some sloppy technique used to remove horizontal clash marks?

    Numismatist. 50 year member ANA. Winner of four ANA Heath Literary Awards; three Wayte and Olga Raymond Literary Awards; Numismatist of the Year Award 2009, and Lifetime Achievement Award 2020. Winner numerous NLG Literary Awards.
  • Insider2Insider2 Posts: 14,452 ✭✭✭✭✭

    @yosclimber said: "Could be a die clash, since the lines seem to be uniformly spaced?"

    Thanks for your comments. I disagree as the marks are not caused by a die clash. Did you read what I posted from the nickel book or what the nickel expert posted?

    "@howards posted: "I call them "die fatigue spikes." They always occur along the edges of a coin device and protrude into the fields. My explanation (FOR WHICH I HAVE NO PROOF) is that where the recess in the die for the device meets the field experiences extra stress, and is a likely spot for die failure."

    You see, he has no proof and I don't agree 100% with the nickel expert. We posted before and I forgot his opinion so I asked for it. Now I wish to hear from others. I have been told that MANY OF THESE MARKS are something else. I have done some further research and have possibly found one source for the often repeated "die fatigue" opinion.

    Hopefully, some members here will provide answers to the four SPECIFIC QUESTIONS I posted above. THANKS!

  • Insider2Insider2 Posts: 14,452 ✭✭✭✭✭

    @CaptHenway said:
    I am familiar with these irregular horizontal lines on Shield nickels, and they are not die erosion lines, which tend to be both radial and near the borders. They do not look like clash marks because they are too irregular, but I do not know what caused them. Perhaps the result of some sloppy technique used to remove horizontal clash marks?

    Now we are getting closer to what I was told long ago by Philadelphia Mint employees. Nevertheless, @howards and @BillJones have valid opinions. I hate to pass false info to others and until what the nickel expert said and what I found in the book came to light, I never questioned what I was told and saw on these coins. That's why I'm trying to get opinions of others.

  • CaptHenwayCaptHenway Posts: 31,499 ✭✭✭✭✭

    @RogerB said:
    :) I checked Breen's really very secret papers....He says they are made by "Midnight Minting Mice" who chew at the dies when all is quiet at the mint. His other guess was that the "5" had been cut too quickly and these were speed lines - line in cartoons - showing the 5 was moving vary fast. His last suggestion was "stretch marks" but the next page of Breeen's manuscript was missing.....

    ;)

    That's quite a stretch........

    Numismatist. 50 year member ANA. Winner of four ANA Heath Literary Awards; three Wayte and Olga Raymond Literary Awards; Numismatist of the Year Award 2009, and Lifetime Achievement Award 2020. Winner numerous NLG Literary Awards.
  • yosclimberyosclimber Posts: 4,572 ✭✭✭✭✭
    edited July 19, 2017 12:27PM

    @Insider2 said:
    Did you read what I posted from the nickel book or what the nickel expert posted?

    Yes.
    (I quoted what Howard posted - is he the person you refer to as the nickel expert?)

    What are your thoughts on why this cannot be a clash?
    (Although many lines are uniformly spaced, there are additional lines, so the full set could not have come from a single clash.)

    Here is a classic example of radial die erosion. The lines are not parallel and they are near the edge.

    from
    https://forums.collectors.com/discussion/comment/6418302/#Comment_6418302

  • Insider2Insider2 Posts: 14,452 ✭✭✭✭✭
    edited July 19, 2017 2:45PM

    @yosclimber said: Thanks again for your help. Please take my answer to you as friendly instruction plus a suggestion you may consider in the future.

    Yes, Howard (I don't know his last name and AFAIK we have never met) is the nickel expert. Sorry to say, I'm very sheltered so have never heard of him but I value his posts.

    @yosclimber asks: "What are your thoughts on why this cannot be a clash?"

    On the nickel? I'm really sorry to post this but are you kidding? Just in case you are not "baiting" me for your pleasure :smiley:

    Clashed dies are explained in many references and on the Internet. The Macmillan Encyclopedic Dictionary of Numismatics (an old reference by Richard Doty) defines them as DIES DAMAGED BY BEING STRUCK DIRECTLY AGAINST EACH OTHER, rather than against the surface of a planchet. When this happens, there is often a transfer of parts of the design from each die to the other.

    The neat overlay of the nickel you posted does not match the image I posted in any way. There is no such design on Shield nickels. Therefore, the cause of the "spike" characteristic I've shown is not due to a clashed die.

    @yosclimber posted an image of a Capped Bust half dollar. "Here is a classic example of radial die erosion. The lines are not parallel and they are near the edge."

    While you are correct (VERY nice coin), unfortunately, the die wear you have shown has absolutely no connection to the coin I posted. Now, I feel others will come to this thread and start discussing metal flow and worn dies on your coin rather than answer my questions about the nickel. I suggest that all of us be mindful of this when we post in a discussion.

    Hopefully, another poster or a Shield nickel collector will post an image showing similar "spikes" so we can get back on tract. AFAIK, these spikes are virtually always confined to early Shield nickels. Since nickel was used from 1865 (3c) on, this characteristic may have something to do with the Mint working with a new alloy.

    I'll keep looking for better examples to image.

  • yosclimberyosclimber Posts: 4,572 ✭✭✭✭✭
    edited July 19, 2017 2:56PM

    @Insider2 said:
    ...
    The neat overlay of the nickel you posted does not match the image I posted in any way. There is no such design on Shield nickels. Therefore, the cause of the "spike" characteristic I've shown is not due to a clashed die.

    The overlay actually matches your image in several ways:

    • all the lines are oriented in the proper direction
    • all the lines are parallel
    • most of the lines are a uniform distance from each other

    With an unrepaired clash, we might expect to see longer lines, and on both sides of the 5.
    But the dies could have been lapped (smoothed) to remove most of the long lines, leaving just this remnant.

  • Insider2Insider2 Posts: 14,452 ✭✭✭✭✭

    @yosclimber said:

    @Insider2 said:
    ...
    The neat overlay of the nickel you posted does not match the image I posted in any way. There is no such design on Shield nickels. Therefore, the cause of the "spike" characteristic I've shown is not due to a clashed die.

    The overlay actually matches your image in several ways:

    • all the lines are oriented in the proper direction
    • all the lines are parallel
    • most of the lines are a uniform distance from each other

    With an unrepaired clash, we might expect to see longer lines, and on both sides of the 5.
    But the dies could have been lapped (smoothed) to remove most of the long lines, leaving just this remnant.

    Excellent, I'm enjoying this discussion. While I don't agree, I'm going to give you an A+ for being a gentleman and a scholar! So far, this is the best explanation; yet it is not what I was told. Additionally, as I remember, the "spikes" can appear at the top of the numeral "5" where there are no shield lines present for the clash mark theory.

    Someone above my pay grade will figure this out for both of us. Until then, I'm going to look for evidence to convince you it is not a clash. :smiley:

  • yosclimberyosclimber Posts: 4,572 ✭✭✭✭✭
    edited July 19, 2017 3:19PM


    A side by side comparison of the photos supports Tom's observation that the lines are too irregular to be clash marks.
    Also, the horizontal lines extend too high on the 5 to be consistent with a clash with the horizontal shield lines.

    Vertical lines above the 5 in certain locations could be consistent with a clash (with the vertical shield lines shown in Howard's overlay).

  • RogerBRogerB Posts: 8,852 ✭✭✭✭✭
    edited July 19, 2017 3:22PM

    Comments by Howard and Bill Jones: [I call them "die fatigue spikes." They always occur along the edges of a coin device and protrude into the fields. My explanation (for which I have no proof) is that where the recess in the die for the device meets the field experiences extra stress, and is a likely spot for die failure.]

    These are consistent - or nearly so- with US Mint sources. According to mint technologists I've talked with, the junction of relief and ground (i.e.: field) is a critical stress point. The more acute this intersection, the greater the likelihood of die cracks and chipping/flaking at those points. This is why all modern dies have curved field intersections and "mushy" delineation between devices/inscriptions and the fields.

    On a shield nickel the transition from field to relief is abrupt and also from minimum to maximum without any transition.

    [PS: This was not mentioned by Breen in his really very secret papers....]

  • CaptHenwayCaptHenway Posts: 31,499 ✭✭✭✭✭

    @yosclimber said:

    A side by side comparison of the photos supports Tom's observation that the lines are too irregular to be clash marks.
    Also, the horizontal lines extend too high on the 5 to be consistent with a clash with the horizontal shield lines.

    Vertical lines above the 5 in certain locations could be consistent with a clash (with the vertical shield lines shown in Howard's overlay).

    Notice also how the lines in question go left from the solid upright and ball of the 5, but not right. To me this suggests something being wiped or scraped or dragged across the die from right to left, and damaging the field of the die where it left the voids that form the upright and the ball and re-encountered the field. What this might have been I do not know.

    Numismatist. 50 year member ANA. Winner of four ANA Heath Literary Awards; three Wayte and Olga Raymond Literary Awards; Numismatist of the Year Award 2009, and Lifetime Achievement Award 2020. Winner numerous NLG Literary Awards.
  • yosclimberyosclimber Posts: 4,572 ✭✭✭✭✭
    edited July 19, 2017 4:45PM

    I looked at the great high resolution images at PCGS CoinFacts and found several examples for 1869 with similar short horizontal lines.

    Since they can occur on both the upper and lower part of the die at the same time, they are not consistent with a clash.

    They seem to appear on either the left side or right side but not both at the same time, consistent with Tom's theory above for the asymmetry.

    from
    pcgscoinfacts.com/CoinImages.aspx?s=3796

  • Insider2Insider2 Posts: 14,452 ✭✭✭✭✭

    @CaptHenway said: "Notice also how the lines in question go left from the solid upright and ball of the 5, but not right. To me this suggests something being wiped or scraped or dragged across the die from right to left, and damaging the field of the die where it left the voids that form the upright and the ball and re-encountered the field. What this might have been I do not know."

    @yosclimber said: "A side by side comparison of the photos supports Tom's observation that the lines are too irregular to be clash marks."

    So are we in agreement that the marks are not caused by die clashing?

    I posted this question today because a nickel expert questioned something I posted somewhere. His opinion refuted what I learned decades ago about the cause of these marks. However, he is the expert in the series and his opinion carries weight. His opinion several months ago and that of others today made me question (for just a moment) what I was taught. I've done some research today and believe I found the source for the "worn die" theory in the literature. Just now I've located a coin that I believe refutes the die chip or worn die theory.

    I learned that the "spikes" result from heavy die polish.

    As a "warm up," I'm posting images of an 1866 Rays nickel. These are not spikes.
    Note that the polish is obvious in a circular direction behind the stars.

    I'm also posting another 1866 Rays nickel with large die polish in a diagonal direction. Note that tiny "spikes" are visible through the lower right side of the numeral in the opposite direction from the coin in my OP. They MATCH the direction of the large die polish on other parts of the nickel!

    I am now satisfied that the "spikes" result from die polish (as I was taught). I hope this "proof" is enough to convince others.

  • yosclimberyosclimber Posts: 4,572 ✭✭✭✭✭
    edited July 19, 2017 6:29PM

    Looks good, although I'm not sure if the tool (short wired brush?) was being used to polish or to remove debris from sunken devices.
    It also could use a theory about why the lines are apparently shorter near the 5 and longer near the stars.
    Perhaps they angled the brush to remove debris from the 5, but used it flatter near the stars?
    https://forums.collectors.com/discussion/721661/what-tools-did-the-mint-workers-have-to-polish-dies-with

  • justcollectingjustcollecting Posts: 190 ✭✭✭

    I think they are stress cracks and stress chips. If you look at the the 5 where the cracks occur there is a sharp transition from one level to the next. Where there is more of a radius on the 5 there are no cracks. I know that on engines used for racing they polish off all of the of the casting marks to reduce the chance of stress cracks developing on the heads and block.

    As for the above comments about die polishing. I think that came after the spikes appeared.

  • Coin FinderCoin Finder Posts: 6,944 ✭✭✭✭✭

    Die fatigue it look like to me.

  • yosclimberyosclimber Posts: 4,572 ✭✭✭✭✭
    edited July 19, 2017 8:15PM

    @justcollecting said:
    ... Where there is more of a radius on the 5 there are no cracks. ...

    Could be true, but I don't know how to observe the radius (roughly the angle between field and edge of 5) from the overhead photos.
    This would not explain the parallel lines, or the asymmetry (lines on one side or the other), I think.

  • howardshowards Posts: 1,239 ✭✭✭

    I've reproduced one of the images above.

    The assertion above is that the lines through the stars are die polishing lines. This is backwards - they are the result of insufficient polishing.

    The original genesis of these lines is the reduction lathe. The reduction lathe traces traces the galvano in a circular pattern, leaving circular raised lines when it is done with the reduction. These lines are supposed to be polished off before the die is placed into service.

    Here is a photo of a shield nickel obverse, where the lathe lines are even more obvious:


    Neither of the above photos shed any light on the question of what causes the die spikes frequently seen coming off the big 5 on the reverse of a shield nickel. There are two totally different causes here, and to use the above photos to justify calling the spikes "die polish" is a non-sequitur.

    An additional reason for accepting that the spikes are in fact die fatigue spikes is that the spikes are always tapered with the narrowest point being farthest away from the device. This is consistent with a flaw in the die beginning at the point where the device meets the field and narrowing as the stress of the flaw decreases with distance from the original point of the flaw.

  • howardshowards Posts: 1,239 ✭✭✭

    The above image (thanks, yosclimber) should convince any of you who are still hanging onto die clash as a possible cause. In the rightmost photo, the spikes off the flag of the 5 are at a 45 degree angle. There is nothing on a shield nickel obverse at that angle at that location.

    IMO, this photo also supports the die fatigue spike theory as the stress runs at right angles to the curvature of the device.

  • Insider2Insider2 Posts: 14,452 ✭✭✭✭✭
    edited July 19, 2017 9:58PM

    I'm going to bed. Will comment tomorrow. Until I do, think about this @howards.

    1. Lines above the field on a coin are incuse in a die...and raised on a HUB. I called the first image polishing lines to keep it simple. I would agree they MAY be from the reducing lathe and were not removed except for one thing...explain how the lines are on the leaves (a deep part of the die) and on the field (the top surface of the die) yet were not polished out.

    2. The transfer process does not leave tooling (heavy polish) in one direction into a coin as shown in my second image. I'll be happy to discuss this further but as I wrote, I'll believe what I learned at the Philly Mint until you can bowl me over with proof. :)

    3. Die wear does not look like sharp spikes!!!!!!!!!!!!!!!!! The closest thing to this (worn die) can be seen at five o'clock on the obverse of LDS 1909-S VDB cents and it looks nothing like spikes.

    Goodnight Gentlemen :)

  • howardshowards Posts: 1,239 ✭✭✭
    1. The reducing lathe traverses all of the coin, highs and lows. The lathe lines are in the recesses of the die because they were present on raised areas of the master hub.

    2. Huh? The reducing lathe transfer process does not leave polish lines of any sort.

  • cameonut2011cameonut2011 Posts: 10,060 ✭✭✭✭✭
    edited July 19, 2017 10:18PM

    .

  • howardshowards Posts: 1,239 ✭✭✭
    edited July 19, 2017 11:13PM

    Wow, Insider, we agree on something. Die wear does not look like sharp spikes. But I never said that the spikes are due to die wear. They are due to die metal fatigue, causing a failure (spike).

  • CaptHenwayCaptHenway Posts: 31,499 ✭✭✭✭✭

    The spikes are not die wear, but I cannot see it as die metal fatigue. A single mark, maybe two. But not multiple marks all running in basically the same direction with a consistent tapering effect.

    It must be some kind of die damage. I just cannot think from what.

    Numismatist. 50 year member ANA. Winner of four ANA Heath Literary Awards; three Wayte and Olga Raymond Literary Awards; Numismatist of the Year Award 2009, and Lifetime Achievement Award 2020. Winner numerous NLG Literary Awards.
  • howardshowards Posts: 1,239 ✭✭✭

    AmazonX - it is not at all usual for a clashed die shield nickel to show so many remnants of the upper part of the obverse (showing on the lower part of your photo due to the coin turn). The vertical bars are what one usually sees. That's on the '69. On the '68, I can't see much. Sometimes clashes are quite faint and you have to try photographing them with light from different angles in order to catch the clash.

    The '69 is a great coin!

  • howardshowards Posts: 1,239 ✭✭✭

    And now for the other side of the coin... Here's the best obverse shield nickel clash I know about.

  • howardshowards Posts: 1,239 ✭✭✭

    @CaptHenway said:
    The spikes are not die wear, but I cannot see it as die metal fatigue. A single mark, maybe two. But not multiple marks all running in basically the same direction with a consistent tapering effect.

    It must be some kind of die damage. I just cannot think from what.

    Not that Wikipedia is a guaranteed reliable source, but it says:

    Metal fatigue is a weakening of metal due to stress, resulting in an accumulation of small cracks.

  • JRoccoJRocco Posts: 14,277 ✭✭✭✭✭

    Interesting conversation.
    Let me add, back in the mid 90's when the 95 Lincoln DDO craze occurred I picked up a half dozen or so boxes of new cents to search for the variety. I did not find any but came across several anomalies, one of these being the following.
    I found at least 2 or 3 hundred examples of Lincolns with some strange patterned die lines in a few areas on and around Lincoln's portrait. Below are a couple of examples. I sent a few of the cents to Mike Diamond for examination about 10 years ago and I do not believe a cause was ever determined.
    Interesting.

    Some coins are just plain "Interesting"
  • Insider2Insider2 Posts: 14,452 ✭✭✭✭✭
    edited July 20, 2017 10:00AM

    @JRocco said:
    Interesting conversation.
    Let me add, back in the mid 90's when the 95 Lincoln DDO craze occurred I picked up a half dozen or so boxes of new cents to search for the variety. I did not find any but came across several anomalies, one of these being the following.
    I found at least 2 or 3 hundred examples of Lincolns with some strange patterned die lines in a few areas on and around Lincoln's portrait. Below are a couple of examples. I sent a few of the cents to Mike Diamond for examination about 10 years ago and I do not believe a cause was ever determined.
    Interesting.

    I've seen one of these.

    Very busy at work. Later today, I have more to add to thread as promised.

  • Insider2Insider2 Posts: 14,452 ✭✭✭✭✭
    edited July 20, 2017 8:05PM

    @howards Thanks for your input. So far we just disagree on a few things. It is not personal, I wish to get to the truth if possible after all these years.

    Next. I'm responsible for screwing up this thread! :( Now we are discussing die polish, die clashes, and lathe marks!

    Hopefully, there will be no more posts about clashes. After this post, the lathe mark question MAY still be open for discussion. Nevertheless, lathe marks have nothing to do with the "spike" question. I stupidly posted an image of concentric marks (I called them die polish) behind the design of a nickel so members could get an idea of marks commonly seen on '66 and '67 Shield nickels.

    As for the spikes, let's all try to figure their cause together.

    @howards found this: "Not that Wikipedia is a guaranteed reliable source, but it says: Metal fatigue is a weakening of metal due to stress, resulting in an accumulation of small cracks."

    While I agree with this...bend a 1/16th inch piece of aluminum stock back and forth and you will see the stress cracks that are mentioned in Wikipedia. You can also see evidence of stress in the surface of many large crowns and 8 Reales. The appearance of THIS TYPE OF STRESS on U.S. coins is either extremely rare or none existent. Bent U.S. coins such as colonial silver DO NOT COUNT. The other kind of "stress cracks" occur in a radial direction (especially found on the edges of struck ancients). When seen on more modern coins, I call them cracked planchets.
    My point is this. Worn dies or die fatigue rarely looks like "an accumulation of small cracks" UNLESS we wish to call the ridges found (for one example) around the letters of large cents small cracks. I do not.

    @howards continued: "Wow, Insider, we agree on something. Die wear does not look like sharp spikes."

    I can get real picky here...LOL. I can find instances where it does; however, that will screw up this thread even more so I'm in agreement. Die wear does not look like sharp spikes.

    @howards also said: "But I never said that the spikes are due to die wear. They are due to die metal fatigue, causing a failure (spike). "

    We have a problem here. AFAIK a worn die and a fatigued die are used interchangeably. Now if you wish to be picky...LOL; I guess a collapsed die (die fatigue) is completely different from a worn one. Since I don't make a distinction between these two terms, please explain the difference and what a nickel struck with a fatigued die should look like.

    @howards said: "The assertion above is that the lines through the stars are die polishing lines. This is backwards - they are the result of insufficient polishing. The original genesis of these lines is the reduction lathe. The reduction lathe traces the galvano in a circular pattern, leaving circular raised lines when it is done with the reduction. These lines are supposed to be polished off before the die is placed into service."

    For the time being, I'm going to leave this open for this reason. I have never seen lathe lines on any coin that are this large, fat, and coarse. I have read in From Mine to Mint that Hill's reducing lathe did not reach the Mint until 1867. This was an improved machine to transfer designs on to a hub. Here is the rub...

    In my experience, this type of crude lines ONLY is seen on early Shield nickels. Since the "older" lathe had been making hubs without this characteristic, it seems to me that the lines have NOTHING to do with the transfer. All I need to do to prove this is to post examples of coins made before 1866 with the usually seen thin concentric lathe lines that were not polished off completely. Agree?

    @howards continued: "Neither of the above photos shed any light on the question of what causes the die spikes frequently seen coming off the big 5 on the reverse of a shield nickel. There are two totally different causes here, and to use the above photos to justify calling the spikes "die polish" is a non-sequitur. An additional reason for accepting that the spikes are in fact die fatigue spikes is that the spikes are always tapered with the narrowest point being farthest away from the device. This is consistent with a flaw in the die beginning at the point where the device meets the field and narrowing as the stress of the flaw decreases with distance from the original point of the flaw."

    Now back to the spikes. I have posted an image showing die work (tool marks) on a struck nickel that run in a diagonal direction that ALSO continue out the sides of the "5." These are the spikes we are discussing. In the end, there may be two types of spikes caused by two different reasons. We'll see.

  • justcollectingjustcollecting Posts: 190 ✭✭✭

    My understanding and I could be wrong is that erosion is a flowing and piling up of metal similar to the image below (borrowed from another website)

    Do you notice how a large area is effected. So to answer stupid question 1 &2 is no.
    3. No I have no better images.
    4. I dont believe they they are created by erosion or tooling. They appear as cracks, short deep cracks. Call it what you like metal fatigue or stress cracks.
    Another example would be to take a log and stand it on end and beat it with a sledge hammer a few time and see what happens.

  • dcarrdcarr Posts: 7,936 ✭✭✭✭✭

    @RogerB said:
    Comments by Howard and Bill Jones: [I call them "die fatigue spikes." They always occur along the edges of a coin device and protrude into the fields. My explanation (for which I have no proof) is that where the recess in the die for the device meets the field experiences extra stress, and is a likely spot for die failure.]

    These are consistent - or nearly so- with US Mint sources. According to mint technologists I've talked with, the junction of relief and ground (i.e.: field) is a critical stress point. The more acute this intersection, the greater the likelihood of die cracks and chipping/flaking at those points. This is why all modern dies have curved field intersections and "mushy" delineation between devices/inscriptions and the fields.

    On a shield nickel the transition from field to relief is abrupt and also from minimum to maximum without any transition.

    [PS: This was not mentioned by Breen in his really very secret papers....]

    Note that all the examples shown in this thread, and all the examples that I have seen, have spikes which are generally oriented horizontally in relation to the design. None are vertical or near vertical. If the spikes were caused by "die fatigue" then they would be seen to occur in all directions, perpendicular to the edges of the devices.

    Here is an 1868 that was on Heritage. Note how long the lines are. In my opinion this is cased by some sort of abrasion to the die, not die erosion:

  • yosclimberyosclimber Posts: 4,572 ✭✭✭✭✭
    edited July 20, 2017 6:05PM

    I looked for more examples on PCGS CoinFacts, and found this interesting 1868.
    It has the parallel short spikes angled slightly uphill, on the right sides of several features.

    5 (maybe some shorter lines on the left side, too?)


    D S and stars (note the longer gouges left of the D also)


    stars and perhaps CE

    Given all the parallel lines, this appears to rule out concentric reduction lathe lines (for this specimen).

  • CaptHenwayCaptHenway Posts: 31,499 ✭✭✭✭✭

    Many excellent pictures here. Thank you all for posting them.

    Numismatist. 50 year member ANA. Winner of four ANA Heath Literary Awards; three Wayte and Olga Raymond Literary Awards; Numismatist of the Year Award 2009, and Lifetime Achievement Award 2020. Winner numerous NLG Literary Awards.
  • Insider2Insider2 Posts: 14,452 ✭✭✭✭✭

    @justcollecting said:
    My understanding and I could be wrong is that erosion is a flowing and piling up of metal similar to the image below (borrowed from another website)

    Do you notice how a large area is effected. So to answer stupid question 1 &2 is no.
    3. No I have no better images.
    4. I dont believe they they are created by erosion or tooling. They appear as cracks, short deep cracks. Call it what you like metal fatigue or stress cracks.
    Another example would be to take a log and stand it on end and beat it with a sledge hammer a few time and see what happens.

    Your post shows a coin struck with a worn obverse die. It has nothing to do with either question #1 or #2.

    Thanks for your participation and the neat image. :smiley:

  • Insider2Insider2 Posts: 14,452 ✭✭✭✭✭

    Thank you, Mr. Carr!

    I was told these marks were due to abrasions to the die. I've always called it "polishing" but "tooling" is a much better explanation as the spikes are thick - JUST LIKE THE TOOL MARKS OFTEN SEEN FROM THE DENTICALS OF COUNTERFEIT LIBERTY GOLD COINS.

    Next, I need to find some very thin pano lines on pre-1866 coins to either prove or disprove the raised concentric lines under and on the design elements. So far, @howards belief that they are lathe lines that were not removed completely is the best guess.

  • howardshowards Posts: 1,239 ✭✭✭

    There are lots of random lines on shield nickels. Dies were hurriedly produced and poorly maintained because the mint couldn't keep up with the demand for them.

    We have lots of pictures of different artifacts above. To suppose they are all from a single cause isn't very realistic.

    For example, this image:

    shows a lot of the spikes that we have been discussing (which I have called die fatigue spikes). But I think the longer line underneath the flag of the five is actually a die gouge introduced by a clumsy mint worker. There is of course no way to prove this, but I've looked at zillions (actual count!) of shield nickels, and that artifact most closely matches die gouges on other coins.

    On the other recent photos yosclimber posted, he says that the parallel lines eliminate the possibility that they are lathe lines. He is correct. But they look nothing like posted examples of lathe lines, and I don't think anyone has claimed they might be lathe lines.

    Insider questions the difference between a worn die and a fatigued die. I can only answer as to my intent for the difference as there isn't any universally accepted numismatic terminology to my knowledge. A worn die is a die that has been in service for a long time resulting in degradation of the devices and/or fields. A fatigued die is one in which the metal has undergone some molecular change making it more brittle and subject to cracking. Note that a fatigued die need not have been in service that long - the die preparation techniques were not advanced at the time of shield nickels and improperly annealed dies were likely subject to early failures.

    dcarr questions why we don't see more vertically oriented spikes. If one examines the examples posted so far, one sees that the spikes generally follow the curvature of device at the point where the device meets the field, rather than being strictly horizontal. But I do agree it is curious we do not see, for example, vertical spikes from the top of the big 5. I don't think any of the proposed explanations for the spikes explain that.

    As to the thought of learning more about shield nickel dies from examining the dies of other series, I think you will find this is of limited utility. There simply aren't other series that combine the factors of hurriedly and poorly prepared dies, and extremely hard planchets with which the mint had no previous experience. For example, that you don't find lathe lines on other series could easily point to the mint having more time to properly prepare the dies. I don't think the mint wanted to make poor dies for shield nickels - they were simply overwhelmed by the demand for dies. In the early years of shield nickel manufacture, they would get only perhaps 10000 coins from a die, while they got multiple times that amount of coins from dies of other series.

  • rickoricko Posts: 98,724 ✭✭✭✭✭

    This thread is very interesting... Great discussion ...it appears a conclusion may be within reach. Cheers, RickO

  • Insider2Insider2 Posts: 14,452 ✭✭✭✭✭

    @howards posted: "But I think the longer line underneath the flag of the five is actually a DIE GOUGE introduced by a clumsy mint worker."

    I'm still to busy to reply in full until later but WE FINALLY AGREE. Die gouge, spike, tooling, tool mark done to the die by a tool that produces "spike-like" artifacts! :smiley:

    @howards posted: "As to the thought of learning more about shield nickel dies from examining the dies of other series, I think you will find this is of limited utility."

    Nuts! You claim the bold lines under the stars are from a transfer lathe. So far that makes sense, UNLESS there are no bold lathe lines on any other coins (especially prior to 1866). As of this minute, I've not seen them in "x" years looking at coins of all types, ages, compositions, and nations using a stereo microscope. :wink:

  • Insider2Insider2 Posts: 14,452 ✭✭✭✭✭

    Wikipedia says: "Metal fatigue is a weakening of metal due to stress, resulting in an accumulation of small cracks."

    Though you all would like to see an example of this on an Edward VI shilling from the 16th century.

  • justcollectingjustcollecting Posts: 190 ✭✭✭

    That picture to me looks more like a planchet flaw . The cracks appear to be recessed into the metal. Here are some images of one that I have. I left the images large.

  • howardshowards Posts: 1,239 ✭✭✭

    @justcollecting: You have an RPD second 8 south!

  • Insider2Insider2 Posts: 14,452 ✭✭✭✭✭

    @justcollecting said: "That picture to me looks more like a planchet flaw . The cracks appear to be recessed into the metal. Here are some images of one that I have. I left the images large.

    The lines on the coin I imaged ARE into the coin. I've clearly explained what caused them. The die breaks on your nickel are completely different - they are raised on the coin.

    Your other images are the "tooling spikes" we are discussing.

  • RayboRaybo Posts: 5,273 ✭✭✭✭✭

    Shield Nickels are the coolest!

  • howardshowards Posts: 1,239 ✭✭✭

    @Raybo said:
    Shield Nickels are the coolest!

    You're probably gonna get some disagreement.

    But I'm solidly behind this idea!

  • Insider2Insider2 Posts: 14,452 ✭✭✭✭✭

    @howards

    I may have asked this a few months ago, have you written a book I can buy?

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