Toured the Denver Mint on Thursday 0

[VKurtB]

There were no tours on Juneteenth, a Wednesday. Our ANA tour was the following day, Thursday. Federal employees all. Guess how much activity was apparent on the Thursday after a Wednesday holiday. I imagine the July 5 tours will see even less activity. Not a single press, nor conveyor of blanks, nor upsetting machine, was moving. But there was ONE ROOM where activity was abuzz. The robots that pack SPECIALLY STRUCK Denver circulation-style coins for 2024 Uncirculated Sets and the humans inspecting the finished holders were chugging away, doing their duties. The new information I got was that Uncirculated Sets are now containing specially struck coins struck at a far lower speed and higher striking pressure than "intended for circulation" counterparts are. Who knew and didn't tell?

[Henri Charriere]

I vote that these SMS be officially recognized as such. All in favor, say Aye! 

[cladking]

On 6/21/2024 at 8:51 PM, VKurtB said:

The new information I got was that Uncirculated Sets are now containing specially struck coins struck at a far lower speed and higher striking pressure than "intended for circulation" counterparts are. Who knew and didn't tell?

They've done many other things to ,make mint sets nice as well.  The biggest thing that they do consistently is to use nice fresh dies but also often use better planchets, special presses, and better hubbing on dies.  They also often wash the coins.   They've been doing these things since 1965 but until 1996 they claimed they were just like the coins coming off the regular presses. In a sense they were since mint set coins are, in theory, identical to regular production coins in that every coin is engineered to be perfect. But in the real world almost no regular production coin comes out perfect and it's far more common for mint set coins. 

In 1996 they changed their advertising to include some of these facts about mint set coin production.

The reason this isn't common knowledge is that nobody collects moderns and the mint has said something that we interpret to mean the coins are identical far more times and in far more places than they have admitted the coins are made in such a way that there are many more Gems.  In many dates the incidence of Gems simply approaches zero.  I have never seen a true Gem so I can't give a meaningful estimate of their incidence.  But in mint sets usually about 2% are Gems and it can be far higher for something like an '88-D cent where more than half are fully Gem.  

It hardly matters anyway because for most moderns there are almost no BU rolls and all the coins come from mint sets.  

[Henri Charriere]

On 6/22/2024 at 8:47 AM, cladking said:

.... The reason this isn't common knowledge is that nobody collects moderns ...

Once again, it depends on your definition of moderns.

In a local NYC paper. a well-known pawnbroker in the first of a two-part ad series, asserts moderns are coins minted after 1600. 

[RWB]

Production modifications for mint set coins dates back to at least 2010, according to the Philadelphia Mint Plant Manager at that time. They were also looking for ways to minimize contact damage while maintaining productivity. What helped for one denomination, often did not work for a different denomination.

[powermad5000]

On 6/21/2024 at 8:51 PM, VKurtB said:

The new information I got was that Uncirculated Sets are now containing specially struck coins struck at a far lower speed and higher striking pressure than "intended for circulation" counterparts are. Who knew and didn't tell?

Nice to get firsthand information like this and not hearsay. I will be interested to see what the coins in these sets look like.

[VKurtB]

On 6/22/2024 at 10:17 AM, RWB said:

Production modifications for mint set coins dates back to at least 2010, according to the Philadelphia Mint Plant Manager at that time. They were also looking for ways to minimize contact damage while maintaining productivity. What helped for one denomination, often did not work for a different denomination.

2010 is a very good estimate of the changeover. When they started using the harder plastic blister packaging for mint sets, they were already using the higher precision presses for the coins. The most recent packaging change was the "dimples in the blisters" that caused many people to believe the coins had rim dings. They did not. Those "dings" are in the plastic blisters.

[cladking]

On 6/22/2024 at 10:02 AM, Henri Charriere said:

Once again, it depends on your definition of moderns.

In a local NYC paper. a well-known pawnbroker in the first of a two-part ad series, asserts moderns are coins minted after 1600.

Ever since I started studying the great pyramids apparently built ~2750 BC I can't help but have the nagging feeling that all coins are moderns.  When I started collecting coins in 1957 buffalo nickels were 19 years old and virtually ancient.  The states quarters program was more than half over 19 years ago.  

[cladking]

On 6/22/2024 at 11:17 AM, RWB said:

Production modifications for mint set coins dates back to at least 2010, according to the Philadelphia Mint Plant Manager at that time. They were also looking for ways to minimize contact damage while maintaining productivity. What helped for one denomination, often did not work for a different denomination.

How ironic!

When in 1996 the mint first admitted in print that mint set coins were "specially made" they didn't then admit this had been true since 1965 either.  

The more things change the more they stay exactly the same.  

[cladking]

On 6/23/2024 at 7:44 AM, cladking said:

When in 1996 the mint first admitted in print that mint set coins were "specially made" they didn't then admit this had been true since 1965 either.  

I should point out that even after 1996 the mint has stated these are "regular production coins" as well.  Usually the verbiage is "standard uncirculated coinage" but they are still struck under higher force at lower speeds with brand new dies.  Sometimes dies can survive for over a million strikes and even more on pennies but mint set dies are swapped out after only 40,000.  Despite all the rolls and bags of circulation issues I've searched I can't recall ever seeing a coin from a new die.  They are common in mint sets with about three in every 1000 sets.  

Edited Sunday at 01:04 PM by cladking

[cladking]

One can hardly imagine why the mint should be so secretive about mint set production.  Perhaps they feared that if collectors knew they would avoid them as not being representative of circulation coinage so they just referred to them as "standard coin".  Of course once a coin is removed from a mint set it can't be distinguished from a circulation example of comparable quality but the fact is there often is no circulation example of comparable quality and no means to prove it.  Circulation issues on rare occasion come out of the mint almost perfect just like about 2% of mint set coin.  Perhaps they were concerned that mint sets would be more popular and they wanted to make about what they were making.  Note that in 1979 when mint set production began soaring they discontinued them altogether.  

Of course there are many possibilities for this but perhaps the simplest is the correct one: In government (and industry) the right hand never knows what the left hand is doing.  On one hand they made lots of Gems and on the other they had no clue and no means of knowing how or why.  Mints have historically had a love hate relationship with collectors but they do always value one thing we do; preserve nice specimens for the future so getting nice specimens into our hands must be at least some priority for at least some of the workers and staff.  

There have been nice clads made for circulation all along.  If you can find one there will be dozens more in the same bag.  But most rolls and bags contain none at all and there are very very few rolls and bags because most moderns come from mint sets.  

[RWB]

I suggest that the underlying reason for the ambiguous description is that production was under constant change. Rather than raise expectations, the Mint Gods preferred no expectations. (My 2010 meeting with the Plant Manager was not long enough to get into detail, although the unc coin emphasis was on avoiding contact marks.)

[VKurtB]

On 6/23/2024 at 8:58 AM, RWB said:

I suggest that the underlying reason for the ambiguous description is that production was under constant change. Rather than raise expectations, the Mint Gods preferred no expectations. (My 2010 meeting with the Plant Manager was not long enough to get into detail, although the unc coin emphasis was on avoiding contact marks.)

Have you really closely examined a VERY recent mint set/uncirculated set? The coins are stinking immaculate!!! There are MS68's and 69's in there.

[numisport]

On 6/21/2024 at 9:51 PM, VKurtB said:

There were no tours on Juneteenth, a Wednesday. Our ANA tour was the following day, Thursday. Federal employees all. Guess how much activity was apparent on the Thursday after a Wednesday holiday. I imagine the July 5 tours will see even less activity. Not a single press, nor conveyor of blanks, nor upsetting machine, was moving. But there was ONE ROOM where activity was abuzz. The robots that pack SPECIALLY STRUCK Denver circulation-style coins for 2024 Uncirculated Sets and the humans inspecting the finished holders were chugging away, doing their duties. The new information I got was that Uncirculated Sets are now containing specially struck coins struck at a far lower speed and higher striking pressure than "intended for circulation" counterparts are. Who knew and didn't tell?

I have noticed the much better quality of Mint Set Coins of recent years, since about 2015 or 2016. Looks like better handling for fewer contact marks and possible changes in die basining giving the appearance of higher relief. Philadelphia struck coins also have higher quality coins it seems.

[cladking]

On 6/23/2024 at 9:58 AM, RWB said:

I suggest that the underlying reason for the ambiguous description is that production was under constant change. Rather than raise expectations, the Mint Gods preferred no expectations. (My 2010 meeting with the Plant Manager was not long enough to get into detail, although the unc coin emphasis was on avoiding contact marks.)

Marking has been the problem with mint set coins all along. Most are well struck by good dies.  This marking can be virtually universal for some of them.  

There have been changes and variation between years and even within years and the variation affects virtually everything from planchet preparation to packaging.  There are some truly strange and wondrous coins in these sets with perhaps the strangest being a 1966 quarter that is struck by very poorly detailed dies but is often virtually mark free.  There are '80-D nickels and '88-D cents that can be mistaken for frosted proofs.  Each date has a unique luster that can be identified from a distance in some cases.  A '72 has a high luster and a '74 is subdued.  '77's have a sort of matte appearance.  All '75's are tarnished and in cracked and yellowed packaging but the '76 is often OK.  Different techniques were used in die preparation and almost every single parameter.  But most all of these coins are well struck by good dies.  This tends to be unusual for the coins made for circulation.  

Mint quality has waxed and waned all along but with the states quarters they began almost immediately to do a better job both with those made for circulation and for mint sets.  Lots of Gems started appearing in circulation and became more and more typical in the sets.  Before '99 they just didn't have much of an audience for their product.  They certainly tried to do better with mint sets starting in '85 even using burnished planchets but marking, if anything, got worse.  By '96 they had most of the bugs worked out of all their coins but the highest quality coins were still a little unusual. 

Some dates were pretty bad and if they had advertised them as "specially made" some customers would have taken issue with that.  No date was so well made that it didn't have a few clunkers in most sets.  

[VKurtB]

On 6/23/2024 at 2:44 PM, cladking said:

Marking has been the problem with mint set coins all along. Most are well struck by good dies.  This marking can be virtually universal for some of them.  

There have been changes and variation between years and even within years and the variation affects virtually everything from planchet preparation to packaging.  There are some truly strange and wondrous coins in these sets with perhaps the strangest being a 1966 quarter that is struck by very poorly detailed dies but is often virtually mark free.  There are '80-D nickels and '88-D cents that can be mistaken for frosted proofs.  Each date has a unique luster that can be identified from a distance in some cases.  A '72 has a high luster and a '74 is subdued.  '77's have a sort of matte appearance.  All '75's are tarnished and in cracked and yellowed packaging but the '76 is often OK.  Different techniques were used in die preparation and almost every single parameter.  But most all of these coins are well struck by good dies.  This tends to be unusual for the coins made for circulation.  

Mint quality has waxed and waned all along but with the states quarters they began almost immediately to do a better job both with those made for circulation and for mint sets.  Lots of Gems started appearing in circulation and became more and more typical in the sets.  Before '99 they just didn't have much of an audience for their product.  They certainly tried to do better with mint sets starting in '85 even using burnished planchets but marking, if anything, got worse.  By '96 they had most of the bugs worked out of all their coins but the highest quality coins were still a little unusual. 

Some dates were pretty bad and if they had advertised them as "specially made" some customers would have taken issue with that.  No date was so well made that it didn't have a few clunkers in most sets.  

The mint set coins are now struck on the Grabener presses and loaded into tubes from which individual coins are carefully plucked by mechanical robots and placed into the plastic blisters in the red (Denver) and blue (Philadelphia) cards. The circulating coins are made on the horizontal strike Schuler presses.

Edited Sunday at 10:42 PM by VKurtB

[RWB]

"Specially Made" can be ruined by "carelessly handled."

")

[VKurtB]

On 6/23/2024 at 5:03 PM, RWB said:

"Specially Made" can be ruined by "carelessly handled."

")

Yup, sure can. I am guessing that's why human handling has been virtually eliminated.

[cladking]

On 6/23/2024 at 6:09 PM, VKurtB said:

Yup, sure can. I am guessing that's why human handling has been virtually eliminated.

I don't have any known facts to prove it but I believe the mint had been automating some aspects of mint set assemblage in the '70's.  But in 1980 much more became automated.  In the past there there were a few sets with all nice coins but after 1979 this stopped.  Perhaps not coincidentally virtually all '80-D half dollars in mint sets have shallow scrapes on the reverse. I think this is a case of specially made leading to carelessly handled.  

It's a real shame too since this coin was made so extremely well and many escaped becoming marked until right before being inserted into the packaging.  

There are some similar anomalies as well including the nicest dimes of 89-D(?) having a deep short scratch right in front of the bust apparently made coming out of the coining chamber.  

When something goes wrong in an industrial process it can affect the entire production or significant percentages of it.  

[RWB]

Shipping in bags to set assembly was a major culprit, along with coin-to-coin contact when sliding into a press hopper.

[cladking]

On 6/24/2024 at 8:55 AM, RWB said:

Shipping in bags to set assembly was a major culprit, along with coin-to-coin contact when sliding into a press hopper.

It's a wonder any of the mint set coins escaped unscathed.  

It's also been reported that after mint set coins were washed in the 1980's that these coins were then tumbled with ground corn cobbs in something that looked like a cement mixer to dry them.  Even mint set coins were often poorly struck from dies that exhibited a little wear and then chewed up in the equipment before being scraped going into the sets.  The typical mint set coin can charitably be described as "mediocre" but it is almost always better than 99% of the coins made for circulation.  And this goes many times over if you seek a good strike from good dies.  

Of course since 1999 quality has improved across the board and nice coins can be found in bags and sets.   Very high grade coins are still more likely in the sets but most collectors would be satisfied with what can be found in rolls.  Gems are quite common in rolls of some and much less common in others.  

[RWB]

Planchets were cleaned before use and dried in rotating vats of shopped chopped corn cob, and later other absorbents. Coins were not washed or tumbled.

Edited Wednesday at 07:40 PM by RWB

[R__Rash]

On 6/26/2024 at 10:35 AM, RWB said:

Planchets were cleaned before use and dried in rotating vats of shopped corn cob, and later other absorbents. Coins were not washed or tumbled.

No possibility of a dryer coin, determined to be a valuable mint error, atol…….

 

 

 

 

 

[cladking]

On 6/26/2024 at 11:35 AM, RWB said:

Planchets were cleaned before use and dried in rotating vats of shopped chopped corn cob, and later other absorbents. Coins were not washed or tumbled.

This is per Tom DeLorey.  

I first saw it around 2002 when it appeared similarly in an article co-authored by Kari Stone in CoinAge Magazine in an article called "The Mint's Secret coins".  They have always treated these coins as some sort of state secret since special techniques were first employed to produce them in 1965.  (or mebbe '64  )

 

"Yes. The ANA Summer Seminar students used to get great field trips to places like Cripple Creek and/or the Denver Mint. We would usually get to roam around the floor where the coin presses were, and see some other department such as one year we went to the lab where they tested incoming strip, planchets and/or finished coins to see if they were within specs..

In 1981 we went down in the basement where they were packaging up the D-mint (plus S-mint dollar) panel of the annual uncirculated sets, what we call "Mint Sets." Seeing how this giant machine did that was cool, but eventually I wandered off into a side room where there was a stainless steel tank with a lid in the middle of the floor, and over in one corner a hand-cranked cement mixer such as you might see at a small construction site. Next to it was a stack of 100-pound bags of dried, crushed corn cobs and a big scoop.

I caught the attention of our tour guide and casually asked him what all this was for. He said that up on the coining floor they routinely sprayed a light machine oil on the planchets so that they would feed through the coining presses smoothly. Normally it was just left on the finished coins, but they were removing it from the coins intended for the Mint Sets. (I did not say anything then and there, but I remember that the Mint Sets from the 1970's often came with the copper-nickel coins discolored, so perhaps they were trying to prevent this post-packaging discoloration.)

He helpfully explained that a worker would take a bag or half a bag of coins from upstairs and dump them into the cement mixer along with a scoop of the dried crushed corn cob and crank the cement mixer to remove the oil. The cement mixer was then dumped out into a stainless steel basket which was shaken up and down in the tank. He called the liquid in the tank a "de-ox" compound. I later found out it was liquid freon.

I wrote a story about this (can't remember where it appeared) and there was some kerfuffle about the uncirculated coins being treated this way. Perhaps it was mere coincidence, but the Mint did not sell Mint Sets in 1982 and 1983. When they returned in 1984 the quality of the coins did seem better. For one thing, they were not covered with hundreds of tiny nicks and scratches."

 

 

I already knew they were made specially from simple observation and knew dies were swapped out early because there were so many new die strikes.   I also knew that until 1996 the mint had claimed they were identical to coins made for circulation.   But if you want Gem moderns the only place to look is in these sets.  A very few were made for circulation but they were not saved and neither were the bad ones made for circulation.  About 2% of mint set coins were made as Gems.  Nice chBU's tend to be very common for most dates in these sets and usually account for about 75% of mintage.  Most of these sets are long long gone today because they were unwanted and unloved.  

Edited yesterday at 01:13 AM by cladking

[RWB]

Light machine oil was used as described for more than a century. The oil evaporated under he heat creating during striking. Struck coins were not tumbled.

[cladking]

On 6/21/2024 at 8:51 PM, VKurtB said:

Who knew and didn't tell?

There is a very high correlation between the quality of any given coin in mint sets and the graded pops suggesting that most high grade coins are being found in mint sets. Ikes are the only denomination without a very strong correlation between incidence of Gems in sets and graded pops but there is still some correlation. 

I know there are some BU rolls of moderns but these are mostly cents, nickels, and a few half dollars.  There used to be Ike rolls available but these are getting very difficult to find.   Most of the varieties appear in these rolls and some very lightly marked specimens as well.  But roll coins are usually poorly struck and by worn dies.  

Even today it seems relatively few collectors are aware of these facts.  And there are some very knowledgeable collectors who will argue them.  I know a few individuals with great experience pulling Gems (and other goodies) from BU rolls but I've long suspected that many of the rolls they search were rewrapped mint set coins.  Also, most of the searched rolls are 1c and 5c and these were lightly saved in almost every year they weren't heavily saved.  There is also a somewhat weaker correlation between mint set quality and BU roll quality.  

 

Many people seem to think that if mint set coins are "distinct" then they are NCLT and should be collected separately but the simple fact is that some coins from brand new dies did go into circulation.  A new die can easily produce up to a few thousand coins before wear begins to appear.  With hundreds of die pairs each year this means there is a potential for several million Gems to have appeared in BU rolls and bags.  In the real world though many of these dies were not set well and the coins they made got scratched badly even before being bagged.  Rough handling of bags and pallets further reduced the chances of Gems being found.  But then comes the real problem: In order to be found someone had to look for it and nobody was looking.  I've found only about 10 or 12 Gems per year and I've put some small effort into it.  Some dates may not have had any Gems go into circulation and if one did the odds of it being found by a collector were infinitesimal.  

So here we are in 2024 with most of the mint sets gone and most of the coins that had been in them now worn in circulation.  The few surviving sets can be universally tarnished for some dates.  There's no way anyone can tell the origin of a Gem and whether it came from a bag or a mint set.  As the mint said before 1996; the coins are Uncirculated whether they come from a bag or a set.   

I've been yelling all this since 1986 but there is no interest in the message or the coins.  Someday these will be recognized as actual US coins and collectible as such but who knows when.  If they ever are collected people will be surprised just how elusive they all are.  We walk into a coin shop and see old rolls of pennies, bicentennial quarters, rolls of Pacific Coastline nickels, and American Women quarters and just assume you can lay your hands on any modern you want.  Every coin shop has mint sets so how can you tell most are gone now?  

[cladking]

On 6/28/2024 at 10:00 AM, RWB said:

The oil evaporated under he heat creating during striking.

This would be a highly complex process and I'd hardly be surprised if there was some chemical reaction occurring as well.   I would hardly be surprised if this could affect the surface of a coin over time.

I'm quite confident Tom DeLorey reported the reality quite accurately but I'm not in total agreement with him either.  I doubt that the darkening and tarnish of the mint set coins from before 1981 had much to do with oil or anything that might have been left behind.  It is apparently caused almost solely from improper packaging materials as used on the '68- '71, '75, and '77-'80 mint sets.  The other dates aren't fully stable either and this is why most of the few surviving coins of the '60's and '70's are usually tarnished.  

I would guess that these specially made mint set coins had been washed even back to 1965.   

Edited 14 hours ago by cladking

[CaptHenway]

My comment about the discoloration on the early copper-nickel Mint Set coins was mere speculation, but I did see the cement mixer in the Mint Set packaging area in 1981, I did stand close enough to the bags of dried, crushed corn cobs to read the weight on the bag (100 pounds), and I did listen to the Mint worker in the Mint Set packaging area tell me that they did tumble the Mint Set coins in the dried crushed corn cobs in the cement mixer to remove the oil from the coins.

 

I was there. You were not.

 

TD

[cladking]

On 6/28/2024 at 3:40 PM, CaptHenway said:

My comment about the discoloration on the early copper-nickel Mint Set coins was mere speculation, but I did see the cement mixer in the Mint Set packaging area in 1981, I did stand close enough to the bags of dried, crushed corn cobs to read the weight on the bag (100 pounds), and I did listen to the Mint worker in the Mint Set packaging area tell me that they did tumble the Mint Set coins in the dried crushed corn cobs in the cement mixer to remove the oil from the coins.

Yes.  It was phrased as speculation as well.  It's entirely possible that you are correct At least in part.  I don't know but I know enough about the packaging to believe it is the culprit in most cases.  

The process you describe seems to be consistent with a lot of the marking on mint set coins.  There's not much marking from reeding as would be apparent in random high speed collisions but rather numerous low speed collisions.  The scraping was uncommon until 1980.  If marking were imparted falling into hoppers and bins then its severity would be determined largely by how full the hopper was; ie empty hoppers leave coins further to fall.  A lot of mint set marking is falls into a narrow range of collision speeds and appears to be both from metal edges and other coins.  

I always wanted to superglue some thick rubber pads on everything at the mint.  It wouldn't help much with the noise but it would sure increase the number of Gems getting into circulation and mint sets.  

[RWB]

The quantity of oil on planchets was very small and this had been in routine use since long before adoption of automated planchet hoppers in 1910. In the modern era, Simple Green cleaner was used as a final cleaner for planchets. Blanks were dried in ground corn cobs or hardwood saw dust as early as 1795.

I have little doubt the report is correct, but we have only this one knowledgeable observation for guidance. Abrasion of coins tumbled together is an obvious conflict. Were the cobs ground into a saw duct-like consistency? Similar tumblers were used in the 19th century US and Britain to artificially abrade coins to estimate their circulation life before falling below legal tender weight.

Edited 6 hours ago by RWB