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Author Topic: Polygonal coins have many sides and many facets  (Read 30407 times)

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Offline asm

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Re: Polygonal coins have many sides and many facets
« Reply #45 on: May 23, 2011, 11:08:09 AM »
In fact, I inserted the image from the Google Search results. I never noticed that there is something wrong with this coin.

The guy seems to have many of these from different mints.......

Amit
"It Is Better To Light A Candle Than To Curse The Darkness"

Offline <k>

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Re: Polygonal coins have many sides and many facets
« Reply #46 on: May 23, 2011, 11:48:38 AM »
The earliest examples of an intentionally polygonal coin in what is now the UK are the Civil War siege pieces.

Superb images, Alex. Any ideas about what would the earliest machine-struck coin in the world? I suspect the threepence must still be the earliest official machine-struck polygonal coin in the UK.

Offline FosseWay

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Re: Polygonal coins have many sides and many facets
« Reply #47 on: May 23, 2011, 02:01:38 PM »
Credit for the siege coinage images should go to Tony Clayton, not me.  ;) I wish I had examples in my own collection! (I also wish I had a working scanner, but that is something I'm in more of a position to do something about.)

I've been trying to think about deliberately polygonal UK coinage, and I think you're probably right that the 1937-67 3d is the first such piece in the regal coinage series. In terms of the rest of the British Isles, they're followed by the Guernsey 3d (1956 and 1959 IIRC, scolloped) and 10s (1966, square):




However, there are numerous examples of non-round machine-made tokens, especially from the second half of the 17th century. There's a square one and a heart-shaped one on the cover of this book on the subject, for example:


Offline <k>

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Re: Polygonal coins have many sides and many facets
« Reply #48 on: May 23, 2011, 03:11:48 PM »
I have the two Guernsey pieces - they're beauties. I'm surprised by some of the machine-struck pieces. I know little about the technology of coining, so I assumed that machine-struck coins would always be perfectly geometrical, but some of these look home-made!

Offline <k>

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Re: Polygonal coins have many sides and many facets
« Reply #49 on: May 23, 2011, 03:19:27 PM »
Let me pose the question now to our members: what is the EARLIEST use of a polygonal coin or token in YOUR country? Or in the countries whose coins most interest you, or in the countries that are part of your area of expertise?

Offline <k>

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Re: Polygonal coins have many sides and many facets
« Reply #50 on: May 23, 2011, 03:30:27 PM »
It is a fact that bimetallic coins are more expensive to produce than others. For that reason, they are used only for the higher denominations. But what about polygonal coins - are they more expensive to produce than circular ones? In the UK, our 20p coin is a heptagon - but you will find hardly anything these days that costs only 20p. And the UK threepence was a low value coin - though it still bought more than 20p does today!

Which cost factors would be affected by the shape of the coin? Again, I know little about this area. Is the production of a die for a polygonal coin any more difficult or expensive than for a circular coin? And when you have cut your blanks, will there be more scrap or wastage if the blanks are polygonal? Are there any other factors to consider? I have read somewhere that the manufacture of round teabags produces more scrap material than rectangular ones - it sounds logical but I don't know whether it's true.  :D  The same could be true for coins, but rectangular coins are never truly rectangular, because they have rounded edges.

« Last Edit: May 23, 2011, 03:43:30 PM by coffeetime »

Offline FosseWay

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Re: Polygonal coins have many sides and many facets
« Reply #51 on: May 23, 2011, 03:42:55 PM »
Yes, you don't seem to get four-sided machine-made coins with sharp corners. That being the case, I'd imagine the shape that makes the best use of the metal is the hexagon, yet we don't see many hexagonal coins. It is true, though, that scrap from the blank production process can easily be reincorporated into the next batch of metal in a way that (e.g.) teabag paper can't AFAIK.

If metal wastage was a major problem, we'd probably see fewer round coins. That being the case, I don't suppose it's a major deal. And I'd imagine that the cost of actually cutting the metal with a machine is the same once you've designed the cutting mechanism. If you have a cutter that emits 12-sided planchets, it will continue to do so until you tell it to stop in the same way as one that emits circular planchets will.

Bimetallic coins may be more expensive to produce, but they are nevertheless attested fairly early -- in the British context, more or less concurrently with polygonal machine-struck coins. The halfpennies with a tin plug in the 1680s/1690s spring to mind, plus various Victorian and early 20th-century tokens and Spielgeld.

BTW I think you might be right that the heart-shaped and square tokens on that book cover are hand-cut. I kind of presumed that they'd be machine made if the merchant wanted hundreds of them (which presumably he did, as they're not vanishingly rare, unlike the siege coinage), but then again, back then labour was cheap and machines expensive/non-existent.

Offline <k>

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Re: Polygonal coins have many sides and many facets
« Reply #52 on: May 24, 2011, 03:54:09 PM »
Click on the link below to read an illustrated topic about heptagonal coins from all over the world:

An Alphabet of Heptagons


« Last Edit: May 25, 2011, 03:03:34 AM by coffeetime »

Offline villa66

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Re: Polygonal coins have many sides and many facets
« Reply #53 on: May 25, 2011, 08:19:41 AM »
...But what about polygonal coins - are they more expensive to produce than circular ones?...Is the production of a die for a polygonal coin any more difficult or expensive than for a circular coin?....


Die life must be an issue....I think I remember that during WWII and for some years after, the corners of the brass threepence were rounded somewhat so as to increase production.

 :) v.

Offline villa66

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Re: Polygonal coins have many sides and many facets
« Reply #54 on: May 25, 2011, 08:27:28 AM »
Let me pose the question now to our members: what is the EARLIEST use of a polygonal coin or token in YOUR country? Or in the countries whose coins most interest you, or in the countries that are part of your area of expertise?

For the Canadian coinage that begins in 1858, the earliest polygonal coin must be the 1942 tombac 5-cent piece.

 :) v.

Offline <k>

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Re: Polygonal coins have many sides and many facets
« Reply #55 on: May 25, 2011, 09:20:09 AM »
Die life must be an issue....I think I remember that during WWII and for some years after, the corners of the brass threepence were rounded somewhat so as to increase production.

Thanks, villa66. I never knew that. Then again, my knowledge of production is not great.  :D

For the Canadian coinage that begins in 1858, the earliest polygonal coin must be the 1942 tombac 5-cent piece.

And the 1930s for our UK threepence. Definitely seems like a 20th century thing for modern machine-struck circulation coins.

Offline <k>

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Re: Polygonal coins have many sides and many facets
« Reply #56 on: May 25, 2011, 06:41:36 PM »
We've talked about how chunky the old British brass threepence was. I decided to compare it with our modern chunky friend, the UK pound coin, also made of brass or nickel-brass. The threepence had a thickness of 2.55mm, compared to 3.15mm for the pound coin. So, swallowing a pound coin would in theory be more painful than swallowing a threepence. I've always thought our UK round pound was TOO thick - 2mm would be enough to distinguish it from the other coins.

Anyone fancy a pound-coin-swallowing contest?  ;D

Offline villa66

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Re: Polygonal coins have many sides and many facets
« Reply #57 on: May 26, 2011, 05:13:34 AM »
Let me pose the question now to our members: what is the EARLIEST use of a polygonal coin or token in YOUR country? Or in the countries whose coins most interest you, or in the countries that are part of your area of expertise?

For the American coinage initiated by the Mint Act of 1792, the earliest appearance of a polygonal coin must be the octagonal 50-dollar piece dated 1915 and struck in San Francisco.

:) v.

Offline Bimat

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Polygonal coins have many sides and many facets
« Reply #58 on: May 26, 2011, 06:16:12 PM »
Some obsolete Indian coins:

Half Anna:



One Paisa:



2 Naye (new) Paise:



5 Paise:



2 Paise:



3 Paise:



20 Paise:



And here's a coin having infinite sides :D which soon will be demonetized. 25 Paise.



Aditya
Caution. The low-hanging fruits are still there maybe for a reason.

Offline villa66

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Re: Polygonal coins have many sides and many facets
« Reply #59 on: May 26, 2011, 06:42:03 PM »
India's scalloped coins in copper-nickel were really good-looking pieces. Their heavier mass worked well with the scalloping. Aluminum, however, takes away some of the fun of scalloped coins, I think. Gives them...nah.

I think I'll take some of that back. On reflection, the light weight of a scalloped coin gives it a flyaway quality, somewhat evocative of flower petals in the breeze.

Sometimes when you try to put things into words it changes your mind.

:) v.