Historic Coin Presses
Zoins
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How many historic or decommissioned coin presses are still in operation? I was thinking about this based on the recent thread on the Carson City Mint Coin Press #1 and others. How much information and photos are available on these?
Here are some I can think of:
- "U.S. Mint First Steam Coinage Press" - operated by George Bache Soley, Franklin Institute, Gallery Mint Museum, ANA
- Carson City Mint Coin Press #1 - operated by Nevada State Museum, Carson City
- Philadelphia Mint presses sent to Shanghai Mint around 1923 - operated by Big Tree Coin Company
- Denver Mint Gräbener coin press number GK MP 360 / 31824 - operated by Dan Carr / Moonlight Mint
- San Francisco Mint coin press (service from 1973 and 1998) - used to strike Ron Landis Kellogg slugs
For other presses, I know the Gallery Mint acquired two presses from the estate of Robert McNamara of Heraldic Art.
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That is an interesting question, and one I had not considered. Are old presses sold or, if not, destroyed as scrap metal? I bet Dan Carr knows... Cheers, RickO
Whenever I see that press referenced it is like fingernails on a chalk board to me. If I recall from the photos on DC's website, the actual name as it appears on the press is "Gräbener". Having lived in Germany for several years I know very well that "ä" and "a" are not the same letter. If you want to write that name without the special character you would spell it "Graebener".
Anyway, good topic for a thread. I suspect that many presses are actually multi-use, meaning that once their time as a coining press was done they might have been used for something else (probably more relevant for older and manual presses).
Some years ago I was in Vienna looking to access the Mint store and I accidentally went in the employees' entrance. They had all sorts of old screw presses lining the walkway.
There is an important article in the current issue of Penny-Wise (journal of Early American coppers), by Craig Sholley, discussing whether the "first coin press of the U.S.," on display in the Mint at Philadelphia, is in fact the first press used for U.S. coinage.
Good point @JBK. I had used the text on Dan's website. It would be good to update there as well.
Here's the company's website and they do use "ae" in their domain name and "ä" in their logo:
http://www.graebener-minting.com/
Perhaps one day the ANA will put the press at the front door of headquarters into operation.
They did have Joe Rust of the Gallery Mint Museum put it into operation back in 2000. I'm not sure if it's been used since then.
That would probably require a pretty hefty power source. They already have one in the museum that is not hooked up to anything.
The first toggle presses designed by Franklin Peale could be powered by one person turning the flywheel. The design has a large "mechanical advantage" typical of machines built by practical machinists and engineers of the era. See From Mint to Mint and JNR Spring 2013, "Inventions and innovations of Franklin Peale for the U.S. Mint" for details and illustrations.
If any members on CU have not either bought or borrowed Roger's book to read, you should. Please mention this endorsement as I'm going to request a 25c referral fee for each book sold as of today.
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PS: For those who are interested in toggle press design details, check Issue 1 of Journal of Numismatic Research (JNR) for discussion of Oberlin Smith’s 1896 toggle press patent.
Give us a teaser on what you are working on at the moment.
Finishing final clean-up of long research articles on Gould and Inco "private pattern pieces."
--- But that's off-topic, and I don't want to detract from an interesting thread.
The US Mint consistently refers to them as "Grabener" presses, as in this press release for example:
https://usmint.gov/news/inside-the-mint/west-point-mint-mechanics-keep-coin-presses-running?_ga=2.167826721.1075632563.1516999990-2127433934.1497742735
I could find no usage of "Gaebener" in any US Mint press release or posting.
But I will consider switching to the "ä" character.
This is an interesting list to compile.
There is one entry in the list above that I question: "Philadelphia Mint presses sent to Shanghai Mint around 1923 - operated by Big Tree Coin Company". I saw the article about that. The pictures of their equipment did not look like a surplus US Mint coin press to me. Perhaps what they really had was a US/China surplus punch (blanking) press. The reported coin press looked like a hydraulic unit, I think. Anyway, I would want to see some additional confirmation before I believe that "Big Tree" actually has a surplus US/China Mint coin press.
As Mr. Carr notes, I, too, have seen newspaper references to "coin press" that were really blanking presses or other equipment used in coin production. Further, European auctions sometimes describe any screw-type press as a "coin press" - maybe it increases the bids...?
I appreciate the additional detail, and it does not surprise me that the Mint's press department (or anyone else, for that matter) got it wrong. Most English speakers just don't seem to appreciate that those two little dots over the letter actually mean something and are not just there for decoration. However, the fact remains that "Gräbener" and "Grabener" are two entirely different names. One would not be a substitute for the other under any circumstances in Germany.
For example, in German, Munich is "München" or "Muenchen", and if you wrote "Munchen" I think most Germans would be seriously confused. I could tell you some stories....
Here's a photo of Joe Rust, of the Gallery Mint Museum, next to the first US steam coinage press. He restored and ran the press for the ANA in 2000.
http://arkansasroadstories.com/mint.html
I still haven't heard back from the Mint curator. Looks like Joel was right.
Yup. Ron Landis and I hand-cranked the press when the March 23, 2000 celebration didn't go as planned because the feed tooling was so worn. Once you got the flywheel up to speed, it didn't take much effort to keep it there. Good physic lesson on storing kinetic energy. If I recall, they used like a 5 HP electric motor at the ANA.
That's awesome @Rittenhouse. I wish I had been there. I have the first 6 pieces struck as well as a number of errors like the one below. This particular error has two planchets struck together and it was called "The Train Wreck" by a GMM member. Do you remember this one?
It would have been great to be there given all the activity and discussion. I imagine it may have been like in 1836 when they created the first medals in Feb and it didn't work out so they had to do to regular run in May, ending up with medals with both dates. These are great pieces for me because I collect both ANA medals and GMM medals so it's a nice crossover.
Do you have any photos of the press in operation at the time?
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As best I can recall, that’s not one of them. The problem ones we struck were all off-centers because the feed was worn. The “good ones” Ron and I struck were all perfectly centered because I hand placed the planchet on the lower die and then we cracked the press. We did like 5 or 6 copper, 2 or 3 silver, and 1 gold.
The gold was a bear to strike. Gold is so soft it does not flow into the devices readily so it takes far ore pressure than silver or copper. Look at the 1902 Mint Report. The striking pressure for a double eagle is like 180 tons and a silver dollar is like 160. While I’m one of the two living people to have hand-struck gold on an actual Mint press, I never want to do it again.
But it was a blast to have handled such a historic piece of equipment. I can still recall the day I figured out the press in the basement of the Franklin Institute was the original press from 1836. I had seen it a a child in the 1960s when you could drop a cent in a slot and the press would overstrike it into an FI medalet.
I confirmed it was the original press and then called the ANA. They convinced the FI to allow us to repair it and permanent loaned it to the ANA. Of all the things I’ve achieved both in and outside of numismatics, rescuing the press for the future is my best.
There are photos from the striking but I don’t have them. Perhaps Ron does. The ANA should still have them, I think they were used in articles in CW and The Numismatist.
Good to know on the "Train Wreck" error. I'll ask my GMM friend for some more info on this. I have a few more errors of those I need to take photos of and try to get more info on them. It's great to discuss with people that were there. I heard the press was moved back to Eureka Springs where the rest of the strikes were done after issues were encountered at the ANA.
It's great that you were the one that figured out the Franklin Institute press was the original US Mint press from Merrick, Agnew and Tyler Company that made it's way to George Soley before the Franklin Institute. It must have been an amazing revelation!
This is one of my Franklin Institute medalets that has been reported to have been struck on this press. Is this the design you remember from your visit?
So the planchet must not have been contained by the die or a collar? Just wondering how strikes this far off center could ever happen.
OINK
I'm not sure how these offset double-strike errors happen, but when searching on the bay, it seems they happen quite a bit at the US Mint. Perhaps others can comment.
Would be fun to do some minting and find out from experience.
When discussing old coin presses, please remember that all of the old presses currently available have been rebuilt and modified many times since their original manufacture. While general mechanical principles are the same, details of operation and some parts and part-tolerances will differ. These can create incorrect conclusions about how the press operated a century or more ago.
Look in the 1st issue of JNR for discussion of an 1896 toggle press patent along with the drawings.
I have the dies that were used. Stack's sold them a few years ago. Ron Landis put a couple cuds in them at the end, otherwise they are in good condition. Restrikes anyone
That's really cool! I'm a huge Ron Landis and GMM fan. I would be up for some
The values quoted above are evidently a misprint. Here is a excerpt from the Coiner's notebook circa 1890-1905:
Force required for double eagles and dollars was similar not nowhere close to "180 tons." Die steel could not withstand more than about 150 T/sq in.
Great history lesson!
Roger, the values are correct. They are listed in the 1902 Mint Report. Your coiner's notebook confirms those numbers, show the tonnage for a one dollar coin as 150 to 180 tons.
Your error is in interpreting that value as tons/sq in.
The actual pressure applied to the planchet was much lower than the 150-180 tons. Actually about 85-102 T/sq. in. which is well below the 150 T/sq in. Morgan referred to as the maximum for die steel.
Seems were are saying the same thing in different ways.
No Roger, you're mixing up different metrics. Read the values in the notebook and read the 1902 Mint Report. Both say virtually the same thing. The 1902 report states the coining pressure as 160 tons and notes that the measurement is approximate. The notebook says "Approx Pressure To Coin 150 180." That's the pressure applied by the press.
Now look at the row Approx Pressure Per SQ Inch, where it notes for the dollar 91. Take the dia. of the punched planchet, calc the surface area, divide into 160, and you get 91.
It's an engineering and math thingy.
No. The total force was reported in the range of 150-180 T. The pressure per square inch is exactly as I noted: 85-102 T/sq. in.
Yes, it is a very simple math/engineering matter and the total force is always applied across the area being struck by the die face.
I find the two statements above to be contradictory. I don't know which you mean.
"Pressure per square inch" ?
Such a metric makes no sense and is not useful.
There is either:
total force (tons);
or force (tons) per area (square inches), which is the definition of "pressure".
In other words, pressure is already a measure of tons per square inch.
Pressure per square inch would be like tons per square inch, per square inch.
Roger, Dan is correct. Force is force. Force per unit area is pressure. Do not mix metrics.
For example, I weigh 185 lbs. That is the force I exert whether standing, sitting, or lying down. The pressure (force per unit area) I exert will change depending upon if I am standing, sitting, or lying down as the area of contact changes.
The other point is the total force number in the notebook is the far more accurate estimate. At least that can be directly measured with a calibrated spring-gauge, which is what they used per the 1902 Mint Report. In this application, pressure would be very difficult to directly measure, especially at this time, the techniques and equip to do so simply did not exist. Thus, the pressure number is a derived value obtained by dividing the measured force value by the area of the planchet or finished coin.
As an engineer, I wouldn't have wasted my time calculating the pressure as there are too many variables, such as getting an accurate measurement of the real surface area including the devices and just how parallel the dies were which will cause pressure gradients across the surface. Meaningless metric actually.
Did anyone here take advantage of or have photos of the "specially-automated 1869 press in the Old Mint Museum" in 1976?
I've seen a video of the one at the Philadelphia Mint circa 1992, though I haven't seen any photo or videos of the ones used by the public at Denver, Old SF, or Washington DC.
Interesting discussion on the force required to strike coins of different metals. I have worked with a lot of sterling silver and copper, both of these can be annealed to a very soft state that is very malleable - then when hammered or struck they become work hardened and ring like a bell. Gold toughens up quickly when alloyed, annealed 18K is harder than annealed sterling or copper. Even finer gold alloys such as 990 gold (99% Au 1% titanium) have increased hardness than pure gold. Gold alloys do not anneal as soft as silver alloys and copper, it is not surprising that gold requires more striking force.