Noble | Presidents Letters

Go to content

Main menu:


37th President's Letter by Chris Pilliod

This is my 37th President’s and this one finds me just returning from a Premium Melt Symposium in Philadelphia, PA. Approximately 100 attendees gather every other year from around the globe to discuss specialty alloy melting, forging, new alloys being developed and so on. Topics include the commercial end of business, technical issues, metallurgy and so on. It’s always an assemblage of bitter rivals so I think organizers strive to find relaxing environments, so usually the conference is held in some nice getaways—Lake Tahoe four years ago, Hilton Head Island several times, Naples 10 years ago, and so on. This year was Philly… oh well.

Two of the days the conference is over after lunch and on one of these occasions I took the opportunity to walk from the convention hotel on Rittenhouse Square and perform a walking tour of the four Philadelphia Mint sites in Philadelphia. The first and second mint buildings are long gone, but both the third Mint and the current fourth Mint building are still standing. The 3rd Mint building is now Philadelphia Community College and of course the fourth mint is the one in full production use. I do this every year-- just walk to the four Mint location sites around the downtown area. It’s actually quite a hike as in the muggy Philadelphia summers the four mint locations are quite a hike from each other.

The first Mint first struck coins in the form of Half Dismes in 1792 with Martha Washington’s silverware as melt stock (they would have been made of galvanized steel if they asked for my bachelor place settings). The story is mentioned that the roof was not even completed when they fired up the Press in their rush to show the nation they had begun their own monetary system. After a severe fire in 1816 and then with the rapidly expanding nation and the resultant higher demand of coinage the first mint was shut down in 1833 but the building itself was used by various merchants as a storefront until it was demolished in 1911. A new modern office building stands there now with just a commemorative plaque left that most passersby’s just ignore as they walk down the block to the Liberty Bell.

The second Mint building was commissioned right smack in the heart of the Business District near City Hall and 30 years or so after groundbreaking would become the location where the first Flying Eagle and Indian Cents were struck. It was decommissioned in 1901 and torn down for commercial development even before the first Mint building was razed I believe. Not even a marker exists where the building stood so you need to be a good reader of the city map just to stand on the spot where it was located. I looked around the foyer of the new bank residing there now but didn’t find any 1856 Flying Eagles laying around. But I did find a 1985 Lincoln Cent that looked like it had been run over by about a half million taxis. This area is the heart of the City District and is bustling with pedestrians and taxis honking and so on. Hard to even imagine a mint there now. If you’re in for a walking tour of the four mints this one can be safely skipped.

It’s quite a hike from the second to the third mint building. Back in the turn of the Century it must have felt like an excursion to the suburbs north of the city. Nowadays Spring Garden Street is near-north side and is actually the beginnings of the residential section of town north of the city. The great news is the grand old building is still fully intact as it was constructed in 1901. But once inside there’s not a lot of Mint history left at the 3rd Mint Building, which has been retrofitted into the Philadelphia Community College. The original entry is the main campus entrance and the original bronze plaque boldly pronouncing “3rd US Mint” still greets the visitor above the archway. Inside the confines students and administration scramble around oblivious to their building’s history. Once I stopped a knowledgeable lady employee there with quite a bit of seniority and engaged her in the history of the building. She politely mentioned a few tidbits of information and then confided that in the basement there was “one helluva vault” that I’d love to see but it was off limits to the general public. “That’s where they used to store all the gold”, she continued.

I walked on and found the Library which is actually an addendum to the original mint building. “Did you know they once minted United States coins here?” I queried a couple passing by students. “No, not really,” they replied, “but that’s cool.”

Inside the main foyer in the middle of the building blooms a student art display. In addition about a dozen old black-and-white photos from the glory days of the mint collect dust on a wall near some of the classrooms. Every year I study these photos to figure out exactly what everyone is doing and what the equipment is being utilized for—a couple of them I never have been sure about, most become evident. So I pretty much have everything figured out in the photos. But this year as I studied the photos one teeny-tiny item in the corner of a 8 by 10 black-and-white grabbed my eye and I began gazing at it for a long time.

In my intensity I found myself taking off my glasses as my bifocals wouldn’t even allow a close enough study. My head was cocked to get a good angle and my nose was dang near pressed up against the photo when I heard a custodian ask, “May I help you????” “No,” I replied embarrassingly, “just enjoyin’ these old photos.”

After about five minutes of that up-close encounter I told myself, “I think right here is a big clue to a numismatic mystery we have been trying to figure out…I wish I would’ve noticed it before.” But I’ll have to save this for an article only after I can collect some needed data to substantiate my thought processing. Look for it in a future Ledger.

I always wrap up my travels at the fourth and current US Mint on the corner of 5th and Arch Streets. Most people outside the building are throwing pennies on Benjamin Franklin’s grave across the street but I just walk by and head into the Mint for the visitor’s tour and a good look at the two screw presses inside. It’s actually a bit of a boring tour unless you like seeing gobs of coins spewing out of the modern Schuler presses—doesn’t do much for me.

But there are a few interesting artifacts on display inside the current Mint building. Peter the Eagle has been embalmed and is mounted above an old Janvier Reducing lathe right next to the Souvenir Shop. A group of tourists from Africa were hovered by the Janvier machine reading the story of Peter and how he made a home near the second US Mint building. It is believed that Peter was the model for the American Eagle appearing on the US Silver Dollars of 1836 through 1839 and then again for our Flying Eagle cents. Legend has it that one day tame old Peter sat perched atop a flywheel of a press when it lerched suddenly and caught him up in the gears. With a broken wing Peter lasted only three more days. The saddened Mint workers has his body mounted and he has remained on display at each of the working mints ever since.

But I was more ensconced in the Reducing lathe, where a 11” copper model of a Mint building was on display as well as the fully-machined hub fixed on the opposite end of the fulcrum. It looked like it was ready to take out and commence striking medals. I studied the belts and reducing gears, trying to figure out how the apparatus worked. My guess is it was 1940’s vintage, but too esoteric even for the Antiques Roadshow. But modern transfer lathes being employed to make Master Hubs are tributes to modern computerization and tooling.

There’s old paintings and doorlocks and bricks from the first Mint building on display, which didn’t do much for me. But the two screw presses on display certainly had my attention, perhaps the highlight of the tour there—even though most don’t even notice them. The first sits in the corner of the entrance foyer just when you pass the metal detectors. A couple years ago I got a real kick out of their Security personnel there. I walked over to the press and studied the assemblage and moving parts—all in remarkable working order. I then pulled out my cellphone to snap some shots. After about six photos the officer came over and sternly warned me, “You’re going to have to leave now—no photos allowed!!!” I looked at him in astonishment, “Are you guys actually worried I’m stealing technology of a screw press from 1795????” I then went on to tell him I’d delete the images if I could stay, and he just turned away.

A larger screw press rests more prominently in the museum area upstairs. Apparently it was used for the larger diameter coinage, while the one in the foyer was probably for dimes and half-dimes and so on. But right next to it is a chair from the original mint, so of course more tourists are interested in that than the screw press.

Years ago I hawked an invite inside and onto the Production floor of the Mint for a personal tour of the Diemaking Shop. I was able to spend time with some of their technical folks and of course, we had quite a lively confabulation to say the least. Man, I just soaked that stuff up, and will try to bring it down to layman’s terms here.Die metallurgy does get a bit confusing for the unindoctrinated but I find diemaking history just as fascinating as Mint history. I have assembled a good bit of data on how diemaking has evolved the past 200 years. At some ANA or FUN Show I will be giving a Powerpoint presentation on what I have found, and it is very interesting.,/br> All over the Die Shop one can observe long bars of steel stacked in bins. Labeled with diameter, heat number, condition, etc. The bars wobble like cooked spaghetti when a forklift carries them— “Man”, you say, I thought those things would be like hickory when moved. But they arrive annealed, and in a very soft condition. Actually, as far as I know the Mint in reality never performs annealing anymore-- or at least I can see no reason why they would need to. The necessity of annealing vanished when the Mint employed single-press hubbing in the 1990’s. Bars used for dies come fully annealed as shipped by the supplier. They are very close to the proper working diameter when they arrive. The Mint can't anneal the bars because they are very long as shipped into the Mint, perhaps 10 to 14 feet long. Because of the exacting operating requirements of the Mint for machining tolerance they prefer to bring the bars in at this length then cut and machine themselves. In reality suppliers such as Carpenter Technology (my employer) use a special type of anneal known as "spheroidized anneal". It is a low temperature anneal , maybe 1400 to 1500F for a very long time (perhaps a day) followed by an extremely slow cool. This makes the die steel "dead soft" as compared to a more standard anneal, which while imparting a lot of softness to the die, would still be too hard to hub.

After polishing and hubbing the dies do work harden somewhat, but the amount of increased hardness is quite minor and more importantly very localized to the surface. Metallurgists often discuss "work harden rates". In other words if you deform two different metals, perhaps nickel and iron, the same exact amount they will NOT harden the same amount and for some metals or alloys they barely work harden at all. On the other hand some metals go nuts... I am working on a project for work-hardened armor plate for the Abrams tank, and this alloy was designed in part reason for fast work-hardening rates. I can't give you the entire composition but will say we discovered that adding nitrogen to metals has an enormous impact on work-hardening rate. I joke to these guys "this stuff gets hard when I stomp on it!!!". We can double the tensile strength with just 20% cold-work. Why work-harden metals? The simple answer is a lot of metals are not "heat treatable".

It gets confusing... the temperatures used for annealing and heat treating are very close and sometimes the same for the same metal. But annealing is a softening operation and heat treating always-- always!-- refers to a hardening operation. In the case of 52100 die steel the Mint will heat to 1500F or so and then quench in oil or polymer, and man, does this stuff get hard-- like Kelsey's knuckles.

A lot of metals can't be heat treated, so metallurgists work harden them to boost the tensile strength (hardness). But even work hardening the most work-hardenable alloys will never get close the hardness the Mint needs for operational dies. Die steels are over 300,000 psi tensile. So a 1" by 1" die steel can lift over 300,000 lbs before it breaks! That's a lot of cars. Get this... this stuff is so hard we don't even pull tensile bars because it would bust up the machines. So the specs just call out Rockwell hardness requirements, a simpler test that correlates well with tensile.

Well, enough about metallurgy… if you absolutely, positively need to learn more, like I said I will be giving a Powerpoint show on this subject at some future Convention.

If you are a charter member or even a long-time member, please send your reminiscences of your early club days to our editor, Rick Snow at

Back to content | Back to main menu