Ike die families and their hubbing

Thanks to Stella Hackel, we Ike people do not have the comprehensive Mint Records that the Van Allen and Mallis had with which to organize their research and writing on the Morgan and Peace Dollar Series.

In the absence of Mint Records it is natural that our understanding of the minting of the Eisenhower Dollar Coin will advance by small steps as proffered theories are tested over time.

The almost overwhelming number of 1971-S Ike Silver Dollar Doubled Dies is a case in point. A little over a decade ago these Ikes were carefully cataloged by two Ike experts, with somewhat differing results.

Wexler cataloged his Ikes by clustering together those with similar patterns of doubling. Brian Allen recently authored a monograph in which he clustered 1971-S double die Ikes with similar patterns of obverse doubling under presumed up-line doubled master dies and doubled working hubs to which he assigned hypothetical catalog numbers.

Tom Kalantzis even more recently reported on his thinking (and Wexler’s) that the groups of similarly doubled 71-S Ikes could and should be linked to hypothetical but specifically cataloged up-line doubled working hubs.

The Ike Group has been moving all along in a somewhat different direction, focusing on the more dramatically doubled Ikes which we are calling “Collectible” while not ignoring the fact that we, too, recognize there are “Families” of Ikes with similar patterns of doubling.

Lastly, Bill Sanders, our resident tool and die expert, for many more than nine months, has been gestating a new explanation of Families of doubled die Ikes with similar patterns of doubling, an explanation that does not require any reference to doubled up-line hubs or dies.

For our May Articles of the Month, we are publishing both Tom’s article (which first appeared in a 2010 issue of NCADD’s publicationThe Hub (with Tom’s permission), and Bill’s article on his explanation of our Families of similarly doubled die Ikes.

After you’re carefully read both articles, please return to this paragraph, it likely will make no sense to you now: both articles force us to think and re-think old notions and both are moving in the same direction, attempting to make sense by thinking out of the box. One key difference, however, is Tom’s implication that the families of similar Ike doubled dies were or could have been hubbed one at a time, even at different times as production demands dictated. Bill’s explanation, on the other hand is based on a key feature of the Mint’s hubbing procedures documented by Margolis and Weinberg (and others): working dies were repetitively hubbed and annealed in groups of roughly 25 at a time.

Fortunately we are not concerned with who may be right and who may be wrong: advancing the flag is a process dependent on authors willing to step outside their comfort zones in order to explore new possibilities. We are fortunate to have two such here and now. Rob


Sanders, Ike Group


The Eisenhower Dollar doubled die Coins have proven challenging to understand and to catalog. Wiles and Wexler created the first catalogs based on individual examples that could be distinguished one from another, even if the differences at times were minor.

The present trend is to clump together and catalog similar doubled die Ikes by an assumed up-line doubled working hub (or master die?), reducing the number of separately cataloged 1971-S Silver doubled die Ikes from well over 100 to perhaps a dozen. In other words, “strikingly similar” groups of doubled die Ikes are grouped together and cataloged with one number created to represent an assumed progenitor up-line doubled working hub.

The Ike Group is moving in a different direction. We will continue to focus on the individual doubled die Ikes even as we recognize “Families” of Ike doubled dies that clearly have very similar patterns of doubling. We are not particularly interested in cataloging assumed up-line doubled working hubs, since the identification of these will always be hypothetical. Collectors do not collect theoretical doubled working hubs! Doubled working hubs do not exist in the present and thus remain hypothetical constructs. Doubled Die Collectors are used to collecting interesting individual doubled die coins and these should continue to remain the primary focus of Ike doubled die collecting.

The Ike Group will identify clusters of Ikes with very similar patterns of doubling as families. We will catalog in each family the catalog number of the prominent members so the primary reference will always be to a specific working doubled die. Thus, in a “Family” of very similar doubled die Ikes, such as Wexler’s cataloged 1971-S Ike Proof DDO-008, DDO-009, DDO-010 and DDO-011, we will catalog DDO-010 (for example) as “71-S SP IG Collectible Family 001–010Wexler” thereby referencing a specific working Die which one of the other authorities have catalogued previously. Our intent is to present pictures and definitions of the doubled die Eisenhower dollars we believe are the most collectible. This compiled collection of data, with thorough cross referencing to other catalogs, will allow the Ike Group to present a clear definition of each doubled die Ike we deem collectible. Our hope is to standardize the TPG’s understanding of each collectible coin.

“But”, you say, “Surely all the ‘Families’ of Ikes with nearly identical doubling came from a single up-line doubled working hub? That’s how the Mint works isn’t it, master hub to master die to working hub to working die? So why not make up a catalog number for that presumed doubled working hub?”

Ah, grasshopper, if numismatics were only that simple. Forgive us if we shatter glass and break bones, but below we present another mechanism that could explain the families of similar Ike doubled dies. Our mechanism is simply the specifics of how working dies are made. 


Let’s break this down into bite-sized bits:

1. Ike working dies were likely hubbed five times to progressively “sink” the full image into the die. It is very likely that the early hubbings (these move the most die steel and thus put the most stress and wear on the working hub) would have been carried out by the most tired of working hubs, or even working hubs that had been modified specifically for the first two or three hubbings. The last two hubbings were likely carried out by the sharpest (newest) working hub in order to impart the sharpest possible image to the working dies. Every die shop in the country would have used this approach to extend the life of their working hubs and get the most out of them.

2. A slow hydraulic press was used instead of a much faster coining-type mechanical press for many reasons including the massive forces required for hubbing and the slower speed required to minimize work hardening. Perhaps the most critical benefit of slow “squeezing” was giving the working die the chance to self-align with the working hub, to “slide into position” for perfect alignment with the working hub. Called “the float”, this mechanism required a tiny but significant amount of free play in the mounting of the working die being hubbed. Without the float it would be nearly impossible to align die and hub accurately enough to prevent wholesale doubling on virtually every die.

3. Due to the “work hardening” induced by each partial hubbing, the working die to-be was re-softened (annealed) after each squeeze so subsequent hubbing(s) wouldn’t damage the die. Annealing was done in groups of 25 dies with exacting attention to accurate and very gradual heating and cooling. But even the best techniques would inevitably cause some distortion to some of dies. Remember also that all such operations are compromises between the ideal and the practical (cost and time factors). We think the Mint may have outsourced annealing of its larger dies to specialty shops because this annealing was so highly technical and difficult. It is unlikely the Mint had that capability in house. Whether in house or outsourced, however, annealing would have been a lengthy procedure with a one to three week turn-around if out-sourced and 5 to 10 days if done in house. The die shop probably re-hubbed the newly annealed working dies from their annealing basket of 25, in succession, after “setting-up” the operation each time the dies came back from heat treatment.

From The Error Coin Encyclopedia, Fourth Edition, Arnold Margolis, NLG and Fred Weinberg, NLG, permission pending, pages 81-82

4. The Mint’s die shop would have used tool and die practices universally employed in die shops of that era so what follows is probably very close to the Philadelphia Mint’s procedures. The hydraulic press is oriented vertically with the working die placed in a holder (the “nest”) on the base of the press. One simple holder is a hole drilled in a plate into which the working die is seated, that hole being slightly larger than the base of the die, perhaps .002” larger, providing the all-important “float” necessary for perfect hub-die alignment.

5. Assuming such a plate was used, it would have been placed on the base of the press with “banking points” to fix x,y orientation(“transitional x,y positioning”). “Banking” refers quite literally to adjustable banks up against which the plate would be secured. Here we have our first mechanism that could potentially introduce transitional doubling (linear, not rotational) into a working die: if the base somehow is not accurately located in X-Y orientation to an extent beyond that which the float could correct, we would have “transitional” doubling of that working die. By the way, we’ll assume that the working hub secured in the arm of the press (the “ram”) is fixed in place, even though some small amount of free play in the ram is unavoidable.

6. In addition, the working die had to be placed in the nest with the correct rotational orientation. This was done by eye, aided by penciled or inscribed lines on the working die and working hub (most likely a scribed line on the die positioning fixture would be “lined-up” with a characteristic on the face of the die). As long as the float could correct the rotational alignment, it was not necessary to have perfect alignment. But if the die worker’s by-eye alignment was off by more than could be corrected by float, one would create rotational doubling on the working die being hubbed. (I believe a later advance used tapered pins for rotational alignment but not during this time period.)

7. An important factor that could have interfered with the necessary float required to create perfect hub-die alignment was the state of the working die’s partial image. Not only could it have been somewhat distorted from annealing, its existing partial “image” was likely created by a more tired, worn, even modified working hub than is now in the ram. Float could have been partially or totally impeded if hub and die could not accurately “seat”, resulting in hub and die jamming and thus producing a doubled die. This potential systems error could conceivably account for families of similarly doubled working dies.
It’s logical that the limited number of working hubs being used to hub a far greater number of working dies would receive careful scrutiny before being used to hub working dies. Careful scrutiny of the Working hubs would have been required to prevent wasting all the effort and expense making the required multitude of working dies. It is perhaps even a stretch to assume that enough theoretically doubled working hubs escaped inspection and detection to account for the known families of similarly doubled working dies.

8. It may be helpful to realize just how small is the x,y or rotational error responsible for even the largest “spreads” one finds on doubled die Ikes. Here is a star from the reverse of Tom Kalantzis’s magnificent 1971-S SP DDE-005 (used with permission):

8a. Yet this spread, measured in thousandths of an inch, has a displacement of approx. 0.002 of an inch or ½ the diameter of a human hair. In rotational terms, 1.0 degree of rotation will cause a movement of 0.017 of an inch, 1 inch out from the pivot point. So we are looking at (for a 1.5 inch diameter Ike with the pivot point at the center) roughly 1.5/2 times 0.017 = 0.013 per degree of rotation. The 0.002 displacement we see in Tom’s Ike would require 0.002/0.013 = 0.0154 degrees, roughly 1/16 of one degree of rotation about the center of the coin. However dramatic, even the “biggest” Ike doubled dies have only tiny transitional or rotational displacements between hubbings.

9. Here’s a summary to wrap up this little visit to the horizon*. Unlike the die set held in fixed position in a coin press, the nesting mechanism by which the working dies are hubbed is x,y and rotationally oriented, opening a door to both transitional (linear) and rotational doubling. in addition we have a real possibility that the sharper hub being used on the 4th and 5th squeezes might not align perfectly with the working hub through float. This opens the door to another mechanism for doubling of individual working dies and for groups of working dies. In other words, the best looking doubled die Ikes could have been produced by a sharp or new working hub in the 4th or 5th hubbing coupled with transitional or rotational repositioning system errors that could easily be repetitive. We do not need to limit our thinking to just hypothetical up-line doubled working hubs to explain families of similar looking doubled die Ikes.

The Ike Group will continue to focus on identifiable “Collectible” doubled die Ikes by looking for doubled die Ikes with generous patterns of doubling and whenever possible for those with distinct markers that can securely identify an individual doubled working die. But just as truck and auto driving instructors preach “horizon driving”, the Ike Group will continue to scan the horizon* for the bigger picture even as we focus on the road immediately ahead.

*Rob is thinking of ending our book with a section called “On the Horizon” in which a number of avant-garde topics will be briefly presented including this one, hence the references to the horizon and to horizon driving.