Thin planchet coins

Post Reply
Coinsforsale
Posts: 14
Joined: Sun May 30, 2021 6:48 pm

Thin planchet coins

Post by Coinsforsale » Sun Jan 30, 2022 11:02 am

Hi. Can anyone help me to understand what processing error results in the production of "thin" planchet coins? I don't see this type of error on the Canada and Coins website. Thanks.

coinguy
Posts: 1343
Joined: Tue Aug 16, 2016 10:03 am
Location: Golden Horseshoe Area

Re: Thin planchet coins

Post by coinguy » Sun Jan 30, 2022 11:37 am

Thin planchets occur when the metal rolls from which the blanks are punched out of are rolled a little too thin.
Any blank from that roll will have a thin planchet which will weigh under tolerance.
The opposite occurs for thick planchets which will weigh over tolerance.

Coinsforsale
Posts: 14
Joined: Sun May 30, 2021 6:48 pm

Re: Thin planchet coins

Post by Coinsforsale » Sun Jan 30, 2022 12:06 pm

Thanks for that, makes sense. Outside of colour and grade determinants, is it safe to assume that the lighter the coin the more value it has? I have a 1985 Canadian penny that weighs in at .6 grams (strike weight apparently was 2.5g) and the diameter looks to be correct. The Reverse is fine but I believe the Obverse is what is referred to as Full Brockage (a dull image of the Reverse). Thoughts on how "thin" coins are valued? I'm a bit new to this so apologies for mistakes in terminology. Thanks again.

TBH
Posts: 248
Joined: Thu Oct 16, 2008 12:09 am
Location: sunshine coast BC

Re: Thin planchet coins

Post by TBH » Sun Jan 30, 2022 12:52 pm

We're gonna need pics for sure.
May be one half of a split coin if one side is struck well and the other side faint.

coinguy
Posts: 1343
Joined: Tue Aug 16, 2016 10:03 am
Location: Golden Horseshoe Area

Re: Thin planchet coins

Post by coinguy » Sun Jan 30, 2022 1:14 pm

If the coin is only .6g, it sounds more like you have a split planchet.
Wish you had said this at the start as there no way it is a thin planchet.
There is a big difference between the two, especially price wise.

Coinsforsale
Posts: 14
Joined: Sun May 30, 2021 6:48 pm

Re: Thin planchet coins

Post by Coinsforsale » Sun Jan 30, 2022 1:58 pm

It really is a delicate specimen, not very thick at all. I was not aware that planchets could split, another example not on the Canada & Coins site. Hopefully these photos are decent.
Attachments
Obverse.jpeg
Obverse.jpeg (481.46 KiB) Viewed 3498 times
Reverse.jpeg
Reverse.jpeg (559.97 KiB) Viewed 3498 times
Thickness.jpeg
Thickness.jpeg (513.16 KiB) Viewed 3498 times

SP67
Posts: 73
Joined: Sun Mar 28, 2021 11:01 am

Re: Thin planchet coins

Post by SP67 » Tue Feb 01, 2022 10:58 am

Interesting coin :o
But with the actual photos quality, it's quite difficult for a good diagnostics.

First, we can see that the reverse shows a strong strike. So this is not a split before strike. In such a case, the strike should be weak on both sides.

That could be a split after strike. But on the "mirror" side, we can't see lamination trace from the actual pictures. Closeup picture would help to clarify this point.

If it's a thin planchet alone in the striking chamber, the strike should be weak not strong. So this is not this situation.

The other option could be the superposition of a thin planchet (or split section) over a normal planchet. Such a scenario could explain the strong strike on the reverse and the ghost mirror image on the other side.
If there's no striation, this is a thin planchet. If some striations are observed, this is a split after strike. In both cases a second planchet shall be in the striking chamber.

=====

Some tricks to improve photo.

If you use a cell phone, just use a holder (small box) to set you cell phone fix and stable above your coin. Adjust the height of the holder to get good resolution and focus. In the way the cell phone will be in the best condition to make focus.

henrysmedford
Posts: 183
Joined: Sat Jun 29, 2013 10:44 am
Location: Oregon

Re: Thin planchet coins

Post by henrysmedford » Tue Feb 01, 2022 7:14 pm

My son found one roll searching a few years back. As that he is disabled a kind person sent into be graded and the price that they came back with for the value was only about a dollar. https://realcent.org/viewtopic.php?f=1 ... ilit=+Thin

SP67
Posts: 73
Joined: Sun Mar 28, 2021 11:01 am

Re: Thin planchet coins

Post by SP67 » Wed Feb 02, 2022 7:57 am

I didn't take time to read the post you are referring, but it's difficult to compare market price between USA and Canada.

For sure the coin presented in this post is higher than 1 $, assuming the coin is legit.

But the question is not there. We are just trying to understand what's happened to that coin.

Coinsforsale
Posts: 14
Joined: Sun May 30, 2021 6:48 pm

Re: Thin planchet coins

Post by Coinsforsale » Wed Feb 02, 2022 6:01 pm

Thanks for the thoughts SP67, and the tips on the photos. I'll try to repost them. From what you say though, is it fair to assume that this is a fairly unique error?

SP67
Posts: 73
Joined: Sun Mar 28, 2021 11:01 am

Re: Thin planchet coins

Post by SP67 » Wed Feb 02, 2022 6:20 pm

This kind of error is always unique, in the sens you can't find 2 coins with exactly the same caracteristics.

But split or thin planchets are not so rare. With some patience you can find few of them.

But for now, we have to confirm that this is a legit error and find the way it was produced.

==========

Other tricks with a cell phone.

You can attached a Magnifier (4x or so) just over the cell phone camera lens. You can use a rubber band to keep it in place and stable. With this setup you can zoom small features on you coin like a microscope :D

SPP-Ottawa
Posts: 26
Joined: Sun Jul 21, 2013 11:55 am

Re: Thin planchet coins

Post by SPP-Ottawa » Fri Feb 18, 2022 8:28 pm

Neat! That planchet looks like it was split before the strike, and then loaded into the striking chamber on top of another blank planchet. That is why it has a rim fin on the reverse. The 'brockage' you see is actually just progressive die transfer (or 'ghosting') from the hammer die striking such a thin piece.

Common for coins from 1980 to 1985, relatively scarce for other years, but you do see split planchets going back to the 1950s.

Thanks for sharing.

Post Reply