Single squeeze hubbing

Discussion in 'Error Coins' started by Pickin and Grinin, Jan 28, 2017.

  1. Pickin and Grinin

    Pickin and Grinin Well-Known Member

    I was looking for some good reads this morning and clicked on the site that got me started in coin collecting. Until this morning I hadn't completely wrapped my head around the Single squeeze hubbing process. I knew that In the olden days they used a reduction lathe. which is why we have the major DDO's 55' 69'S, 70'S 72.
    The below insert is from Wexlers web site.

    "The Mint started using reduction lathes in 1836 to transfer designs from a master model (galvano) to the face of a master hub. These reduction lathes were pantographs with two arms. One arm traced out the design on the galvano while the other reduced it proportionately and cut it into the face of the master hub. It was a very slow and tedious process and took anywhere from a day and a half to two days to complete a master hub.


    In 1996 the Denver Mint opened its own Die making shop. Introducing the single squeeze press to make master dies. upload_2017-1-28_8-37-18.png This was the end of the major DDO or so we thought.

    You can read the full article written by Ken Potter for Numismatic news on Coneca, below is what he wrote about the single Squeeze process, minus the cool pics.

    The United States Mint largely replaced the multiple hubbing process in recent years by the “single squeeze” restrained hubbing process. The “single squeeze” process produces doubled dies that are more often than not, restricted to the central areas of the design. The face of a die blank (referred to as a “die block” in Mint jargon) is machined with a slightly conical configuration to aid in the flow of metal during hubbing. This would indicate that the initial kiss of a hub into a die blank would be restricted to this centralized area before continuing on to fill out the rest of the design. During this process the tip of a tilted die blank would be positioned slightly off location away from the center of the hub into a different area of design than intended. After the initial contact, the pressure of the hub would eventually seat the die blank in proper position, and in turn cause doubling on the affected die.

    (Below referring to 2006, 2014 and 2015 DDO's)

    These recent-date Lincoln cent doubled dies have been breaking the rule of centralized doubling for reasons unknown. There could be any number of reasons for this but if I had to guess based on seeing more and more of these more “classic looking” obverse doubled dies since about 2010, I’d say that some part of the tooling in the hubbing process for cents has seen some wear resulting in a sloppy fit. This could allow for a shift to occur further along into the process of hubbing a die with the shift occurring at near the finishing point of the dies’ production.

    No matter the cause, with the Lincoln cent doubled dies increasing in strength as we move further into this decade, readers need to keep their eyes open for them on future dates. Let us know what you find!

    All photos except those of the 2006 Doubled Die cent are courtesy of John Wexler; 2006 cent images by author. More on the lesser strength 2015 cent doubled dies can be found on John Wexler’s website here:

    Ken Potter is co-author of “Strike It Rich With Pocket Change” and has penned many feature articles for “Numismatic News” and for “World Coin News.” He can be contacted via email at

    I just wanted to add that I am thankful for this day and age, We have all the information that is needed right at our finger tips, with full pics and articles for free.
    Good luck Hunting!
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  3. desertgem

    desertgem MODERATOR Senior Errer Collecktor Moderator

    I am probably in a minority, but since it is a single pressing on the die blank, I do not feel that a doubling effect is a 'doubled die' but machine chatter or "MD" rather than DD from multiple pressings slightly out of position. I understand why some who deal in error coins or collectors who want a 'doubled die' collection of relatively inexpensive coins would 'LOVE' to think of such as important and of high value. But as I do believe in "Collect what you want" I don't press my point to those that do , but to me these are 'machine ( die) chatter errors' . One is human error, and the other is mechanical.
  4. coinman1234

    coinman1234 Not a Well-Known Member

    I agree! I would say it is probably MD except on the die!
  5. Pickin and Grinin

    Pickin and Grinin Well-Known Member

    Single squeeze means that there isn't multiple pressings. And wanting to call it MD, is beyond reasoning.
    Something is moving from start of squeeze to end of squeeze thus, causing a DDO Die.
  6. desertgem

    desertgem MODERATOR Senior Errer Collecktor Moderator

    Then something is loose/ misaligned / or out of calibration. With your analogy, every lincoln from a single master die would have exactly the same doubling, and they don't. Explain how 30-40 different doubling of even a single year lincoln is normal, THAT is the beyond reasoning part? Of course it isn't normal or every coin would have the same defect, and they don't.
  7. Pickin and Grinin

    Pickin and Grinin Well-Known Member

    I wasn't calling it normal at all, I was only specifying that something has to be moving from start to finish, other wise there couldn't be 30 - 40 different DD to a certain year.
  8. mynamespat

    mynamespat Missing Hugs and Handshakes

    As far as I'm concerned the 1995 DDO is the last of the true doubled dies for Lincoln cents. The modern dd's are more akin to machine doubling during die production. One reason there are so many varieties is because the single hub technique makes the dies more disposable. Therefore, less time is spent extending the dies life because of the lowered cost/increased speed of die production- just swap it out for a new one.
    Pickin and Grinin likes this.
  9. Pickin and Grinin

    Pickin and Grinin Well-Known Member

    The Mint showed what it was capable of the years before, Since they started the copper/Zinc. Those Poor dies that they tried to save. To be short they had to cut Die life for the production of Billions of cents every year. Therefore the more variety's.
  10. thomas mozzillo

    thomas mozzillo Supporter! Supporter

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  11. Pickin and Grinin

    Pickin and Grinin Well-Known Member

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  12. Pickin and Grinin

    Pickin and Grinin Well-Known Member

    The 96' Is one that I have been searching for forever in early die state. I have found later die states but the smear included above in Thomas's article makes it appear as DDD.
    thomas mozzillo and mynamespat like this.
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