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 Replies: 15 / Views: 3,350 |
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Moderator
 Australia
16816 Posts |
Hi all, was wondering if the locals could help with a query. Everywhere I look, the composition of Canadian plated-steel coins is listed as "steel". For example, the composition of a plated-steel cent is given on Wikipedia as "94% steel, 1.5% nickel, 4.5% copper". My problem is, from a chemist's point of view, "steel" isn't an element. "Steel" is a weasel-word without a strict definition; the word covers a wide array of alloys, the only thing they all have in common is a high iron content. Does anybody know the actual composition of the steel used in Canadian coinage? Does it actually vary, depending on the supplier of the raw metal? Or is it a carefully guarded secret, kept under wraps to try to foil the counterfeiters? I would have assumed the actual metallurgical composition to be prescribed somewhere in the coinage legislation, but I can't find it. Edits in bold. Sorry about that.  Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis
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Pillar of the Community
 Canada
1775 Posts |
Quote:
the composition of a steel-clad quarter is given on Wikipedia as "94% steel, 1.5% nickel, 4.5% copper". Good question. I can't say about the steel make up, but I bet Wikipedia may be referring to the nickel and copper plating, not clad, element of the coins composition for those numbers. "We are poor little lambs...who have lost our way...Baa...Baa...Baa"
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Bedrock of the Community
Australia
21786 Posts |
As Sap would already know, but for the benefit of those who don't.,
mild steel is an alloy of iron and carbon in the range of 0.03% to 0.4%.
I agree that 'steel' is a weasel-word, and can understand why the question was asked.
Ferro alloys cover for any alloy of iron and any other metal that will dissolve into iron in alloy form. Stainless steel is an example.
The current circulating coinages of many countries are made of a steel core with a copper-nickel cladding. The coinage of South Africa is an example.
Mild steel would be an excellent core for a circulating coinage, because it can be made to be ductile, and this easily struck for coinage; the obvious problem is that steel rusts easily, and thus needs protection. Copper-nickel cladding is excellent for this purpose.
I haven't really answered Sap's question in relation to Canadian coins:
- is the core a ferro alloy steel, and if so, what is the core composition?,
- is the core mild steel, and if so, what is the percentage of carbon in the alloy?
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Pillar of the Community
Canada
9862 Posts |
It's a secret, to protect the mint's proprietary process of coin production. Each denomination has a unique composition so that each has a different electromagnetic signature to aid in vending, counting and Counterfeit Detection. Quote:
the composition of a steel-clad quarter is given on Wikipedia as "94% steel, 1.5% nickel, 4.5% copper". As I'm sure you're aware Sap there are no clad Canadian coins, and those percentages are way out of whack. I've always found your posts to be both informative and authoritative. 'Sup with this? It's not like you to further the spread of misinformation. "Dipping" is not considered cleaning...
-from PCGS website
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Moderator
 Australia
16816 Posts |
I don't know why I typed "Steel-clad quarter", when I was looking at the WIkipedia page for the penny. Sorry about that. Will edit the OP.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis
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Moderator
United States
188052 Posts |
Quote:
It's a secret, to protect the mint's proprietary process of coin production. As I read this question, that was going to be my best guess. I can understand why they would want to protect this information. |
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Bedrock of the Community
Australia
21786 Posts |
Hardly needs to be much of a 'secret', - any ferro metallurgist who is worth his salt and under contract to a mint,
could easily devise a specification for a ferro alloy or steel, that could meet the mint's requirements.
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Pillar of the Community
United States
883 Posts |
Quote:Each denomination has a unique composition so that each has a different electromagnetic signature to aid in vending, counting and Counterfeit Detection. I am curious to know how differing EM signature works in vending. |
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Pillar of the Community
United States
4233 Posts |
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Pillar of the Community
United States
6493 Posts |
How can it be a secret? I would assume that anyone with the correct metal analysis equipment could arrive at the precise ratios in a few minutes.
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Pillar of the Community
United States
883 Posts |
Thanks kbbpll
It never ceases to amaze me how many hoops engineers have to jump through to try to defeat thieves.
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Pillar of the Community
Canada
6244 Posts |
I will give you the chemestry of material of what it is use. The words are easy: Monolithic Iron. Who say steel has no idea of what is talking. Steel it is a generic name for Iron at different C concentrations %. Here it is the explanation of this Iron use in Canadian coins: https://pubs.acs.org/doi/10.1021/cm300495j |
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Pillar of the Community
Canada
5324 Posts |
One could XRF a recent coin to see if there is any difference between a nickel or dime, my guess they are the same
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Pillar of the Community
Canada
9862 Posts |
Quote:
One could XRF a recent coin to see if there is any difference between a nickel or dime, my guess they are the same According to the mint each denomination is different. "Dipping" is not considered cleaning...
-from PCGS website
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Pillar of the Community
Canada
5324 Posts |
The RCM after the security featured loonies and toonies came on stream also said they could track everyone produced by them, I find this fact highly suspect. Next time I need an XRF I shall bring a nickel and dime along just to be curious |
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Pillar of the Community
Canada
2517 Posts |
EM signatures: There used to be a promotional brochure pdf on the Mint's website ages ago (10-ish years?) about how the multi-ply process plating is applied and how it does in a vending machine, though it's definitely not discussed in-depth. It's not there on the Mint's website anymore, but I found an archived version on archive.org (from the old coinscan/CNPI website, but that's been taken over by a crypto website today). I can't get the link to work here because CCF separates it into two parts that don't work, so I added spaces. Copy this entire chunk below and delete the spaces in between. https://web.archive.org/ web/20180705115745/ http://www.coinscan.com/ technical/mintreports/ MRC115003M_Brochure_Multiply_En_Clientplating.pdf For what it's worth, I also found something on Google Patents about MPPS coins. It's "abandoned", whatever that means. You can Ctrl + F for "steel". "EMS", etc. https://patents.google.com/patent/U...0119865A1/enThere's a related patent owned by "Sherritt Gordon Mines Limited" below... that must have something to do with the Sherritt Mint right? Do they still exist? Probably need a new topic to go into this. |
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Replies: 15 / Views: 3,350 |
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Posted 06/04/2023 11:05 am
