From Ingot to Coin

[leeg]

I found this article in one of my references that arrived yesterday and thought it would be good information to pass along:

 

The Mint floor, showing stored coils of unpunched planchet strip.

 

 

“. . . Actually, the information presented here DOES have a great deal to do with Commemoratives, as the planchet making process, although no longer a mint function but contracted out to private companies, offers you an insight as to what CAN happen to a coin along the minting cycle before it becomes a coin.

 

The photos were taken by the author (Bill Fivaz) during a special floor tour of the Philadelphia Mint in 1970. The tour was arranged by Arnie Margolis, owner and Editor of ERROR TRENDS COIN MAGAZINE, and we were both allowed to take as many photographs as we wanted throughout the tour. A slide series has been assembled from these photos for educational purposes in case any member wishes to borrow them for their local coin club program, etc. (There is no charge except for $3.00 to cover postage, etc.)

 

When one first sets foot on the Mint floor in Philadelphia, he is immediately aware of the tremendous size of that facility. From the enormous blast furnaces to the seemingly endless finished coil storage areas to the huge Bliss presses that transform the nondescript metal blanks (planchets) into recognizable ‘coins of the realm,’ the magnitude is most impressive, I can assure you.

 

Everything starts at the blast furnaces. Properly assayed metals are melted in these huge fire-belching contraptions and then poured into long, thick ingots.

 

After the stored ingots are poured and cooled, they are picked up by a large gripper crane and moved onto the rolling mill. This machine, through many ‘passes’ of the ingot between the various series of rollers, transforms the thick ingot into a thin strip of metal the prescribed thickness of the coin to be struck from the planchets punched from this strip.

 

Blast Furnace.

 

 

Scrap, ready to go to melt.

 

 

Some Rejected Planchets Being Added Into The Melt.

 

 

Blast furnaces In Background And Long Ingot Slabs Stacked In Front.

 

 

Gripper Crane Moving An Ingot Onto the Rolling Mill.

 

 

The photo above shows a hole in the end of the ingot where air became trapped during the cooling process. When rolling this ingot out to the proper planchet thickness, chances are good that this ‘occluded gas’ void will be stretched out within the strip and may eventually cause a lamination on the planchets punched from that particular area. If not inspected and caught, it could appear as a flake or peeling on the surface of the struck coin.

 

 

Planchet Strip Exiting From The Rolling Mill At The Prescribed Thickness, Ready To Be Coiled.

 

 

Coils Of Planchet Strip, coiled and Waiting To Be Used.

 

 

More Coils Of Planchet Strip, Coiled and Waiting To Be Used.

 

 

The Bonding Mill That Bonds the Copper-Nickel Outer Layers Of The Clad Coinage to the Copper Core.

 

 

Here You See The ‘Webbing Or Planchet Strip With The Holes Punched Out, Exiting The Blanking Press.

 

 

As the appropriate metal strip is fed into the Blanking Presses, a series of gang punches cuts through the strip and produces the blank planchets for that particular denomination.

 

 

‘Webbing’ At The End Of Machine And Going Into A Tote Bin. This Will Be Chopped Up And Added Back Into The Melt (As Previously Seen).

 

 

The Upsetting Mill Which Form The Raised Edges On The Planchets.

 

 

Tote Bins For Blank Planchets.

 

 

The blank planchets now pass through an ‘upsetting mill’ which forms the raised edge to protect the design of the coin as well as to aid in stacking. The planchets are fed through the turning grooved wheel they come out slightly smaller in diameter than when they entered.

 

The ‘Type 2’ (raised edge) blank planchets are then stored in large tote bins (on wheel) until needed for the striking presses. As you can see in the above photo, the 5 cent and 25 cent bins are side by side and it would be easy to mistake one for the other if the worker wasn’t careful. It is not uncommon for a blank planchet from one denomination to become lodged in a crevice of a tote bin used for several different denominations and get mixed in with other different sized blanks. This is a major reason why we sometimes find a quarter struck on a 5 cent planchet, a cent on a 10 cent planchet, etc.

 

The blank planchets are fed down long chutes to the coining presses, ready to be struck by the dies. If planchets jam in these chutes, none are deposited in the collar prior to striking and the two dies (the reverse on the bottom and the obverse on the top) strike together, transferring their designs, or portions thereof, on each other. These are referred to as ‘clash marks’, and will appear on each coin struck by those dies until they are removed from the press and polished or retired from service completely. As you know, clash marks are frequently used in determining the authenticity of many commemoratives and play an important part in determining various die stages on coins.

 

 

No description in my reference for this image.

 

 

Striking Chamber With Obverse (Hammer) Die In The Raised Position.

 

 

Obverse Die Descending To Strike the Planchet.

 

 

The following two photos offer a seldom seen sight—the first is a box of ‘raw’ dies, before they have been hubbed or impressed by the appropriate design. Note that they are conical in shape in order to more readily accept the design from the hub. Several impressions are required by the (positive) hub in order to produce the desired depth and clarity in the (incuse) die. It is during this hubbing process that doubled dies occur, primarily due to improper hub-to-die alignment.

 

 

Unfinished Dies, Prior To Hubbing.

 

 

HUB (Top). This Is A Positive (Raised, As On The Actual Coin) Image. DIE (Bottom). A Negative (Incuse) Impression, Ready For Coin Production.

 

 

As the new coins leave the striking area, they are fed through large hoppers to a counting and bagging area. In the last two photos we see them coming down the trough to be counted and the (sic) bagged.

 

 

 

 

The bags are stored at the mint until shipped to the various Federal Reserve Banks upon request.

 

The Minting Process – sketched briefly and basically for you in this article, is a valuable tool in helping you understand not only various abnormalities on coins, but many aspects of grading as well.“1

 

 

1. The Commemorative Trail, the Newsletter of the Society for U.S. Commemorative Coins, From Ingot to Coin, or … ‘So You Want to Start a Mint?’, by Bill Fivaz, Winter, 1985, p. 23-31.

 

 

I hope you enjoyed this.

 

 

 

[BillJones]

Thank you ever so much for posting this, Leeg. I have copied it to my information file. It will be of great use when I speak to my local clubs.

 

If every collector knew more about how coins are made, they would have a better grasp concerning the nature of mint errors and counterfeits. Unfortunately many collectors find this information too boring to learn.

 

And hats off to Bill Faze in his ability to get to take pictures to illustrate the process. If the mint were more willing to educate collectors, they would have more allies in the fight against counterfeits.

[cpm9ball]

Thanks, Lee! That was very interesting.

 

Chris

[rockhobby]

Nice read Lee......thanks for sharing.

 

 

 

Doug

[physics-fan3.14]

That was one of the coolest and most interesting posts I've seen in a long time. Thanks!

[RWB]

The photo labeled "Tote Bins For Blank Planchets" shows a bin for condemned nickels and quarters, not good planchets.

 

The processes illustrated were in use for about 20 years, but are now obsolete.

 

It would be good if someone wrote a solid research article about how coins were made during that period, and another article about how they are made now. (From Mint to Mint covers earlier toggle press production.)

[cpm9ball]

The photo labeled "Tote Bins For Blank Planchets" shows a bin for condemned nickels and quarters, not good planchets.

 

The processes illustrated were in use for about 20 years, but are now obsolete.

 

It would be good if someone wrote a solid research article about how coins were made during that period, and another article about how they are made now. (From Mint to Mint covers earlier toggle press production.)

 

It would be EXTREMELY HELPFUL on another forum I won't mention.

 

Chris

[RWB]

A forum for "unmentionables?" Is that, like, Elliot Ness and that kind of, like, stuff, like? That's, like, so old-timie, like, the Roman Empire and stuff and when the Greek guy fell in the bathtub and got hit on the head with a apple and shouted "This sucks" or "vacuum ting" or something like that, uh, yeah....

[cpm9ball]

A forum for "unmentionables?" Is that, like, Elliot Ness and that kind of, like, stuff, like? That's, like, so old-timie, like, the Roman Empire and stuff and when the Greek guy fell in the bathtub and got hit on the head with a apple and shouted "This sucks" or "vacuum ting" or something like that, uh, yeah....

 

So! You post there, too!

 

Chris

[leeg]

Thank you ever so much for posting this, Leeg. I have copied it to my information file. It will be of great use when I speak to my local clubs.

 

If every collector knew more about how coins are made, they would have a better grasp concerning the nature of mint errors and counterfeits. Unfortunately many collectors find this information too boring to learn.

 

And hats off to Bill Faze in his ability to get to take pictures to illustrate the process. If the mint were more willing to educate collectors, they would have more allies in the fight against counterfeits.

 

Thanks Bill, glad someone can put it to good use.

 

Thanks also to everyone else who posted.

 

 

(thumbs u