I was returning some 50c to a coin counting machine, and 1 coin was rejected a couple of times.
I looked a bit closer, and it is noticably thinner than normal.
I weighed it today and it was 13.36g compared to 15.47g for another 50c.
I also measured the thickness using vernier calipers, and it was 2.06mm compared to 2.33mm for the normal coin.
So is that actually an error coin? You'd assume so! Nice one, any pics?
I think so.
I cannot see any way that it got thinner after production.
I'll try to put some pics up.
Either can I, nice pick up
I would expect it is a little weakly struck
Yes, is there weakness present?
I don't think so. I need to take a closer look, but I think it just looks fairly well circulated.
I think the photo I have on my phone of the coin on the scales is too large to upload, but that looks pretty normal.
Is there any way it could have been done by someone on purpose?
Quote from: 'enworb' pid='3703' dateline='1353498562'I would expect it is a little weakly struck
Why would a weakly struck coin weigh less that a well struck coin? They don't loss weight in the minting process do they? Or am I missing something?
I think the idea is that the press stops at a certain point, so would not put as much pressure on a thinner blank?
Does anyone confirm if that is actually how it works?
Quote from: 'AaronG' pid='3718' dateline='1353540292'Is there any way it could have been done by someone on purpose?
I have read that acid has been used to make fake thin coins. I think the discussion was about a 2c coin.
If that was done on this one, I think the diameter of the con would have smaller too as all surfaces would be eaten away.
I will measure the diameter and report back.
Does anyone know how acid affects a 50c?
I don’t know?
Then you wouldn’t get a die clash..
Quote from: 'Australian coin' pid='3730' dateline='1353548690'I don’t know?
Then you wouldn’t get a die clash..
I agree, but I would expect more than just minor marks if the dies hit each other with full force....
Yeah that makes sense, maybe its something to do with area and volume of the planchet.
Ah I have just got a brain strain.
Quote from: 'Ozcoins' pid='3725' dateline='1353547505'I have read that acid has been used to make fake thin coins. I think the discussion was about a 2c coin.
If that was done on this one, I think the diameter of the con would have smaller too as all surfaces would be eaten away.
I will measure the diameter and report back.
Does anyone know how acid affects a 50c?
An acid damaged coin is pretty easy to pick. They have an orange-peely type surface.
I don't think it was acid then.
My understanding is if it is a thinner planchet there would be less metal to 'fill out the die' and therefore the details wouldnt be struck as fully as normal.
Quote from: 'enworb' pid='3747' dateline='1353560932'My understanding is if it is a thinner planchet there would be less metal to 'fill out the die' and therefore the details wouldnt be struck as fully as normal.
Sorry, I misunderstood.
Could the planchet have actually been meant for another country?
Quote from: 'Graham' pid='3760' dateline='1353584245'Quote from: 'enworb' pid='3747' dateline='1353560932'My understanding is if it is a thinner planchet there would be less metal to 'fill out the die' and therefore the details wouldnt be struck as fully as normal.
Sorry, I misunderstood.
Could the planchet have actually been meant for another country?
I dont think so. It seemed pretty normal, other than being thin.
I dont have it with me right now, so I cant measure the diameter right now.
Some pictures of the thin coin being measured, and a normal coin being measured.
Does anyone else have any thinner than normal decimal coins?
I am interested to see how they compare to this one -particularly the weakly struck idea.
Also does anyone know how common our rare these are?
I will try to get some more pictures up too.
This Aussie $2 (http://www.australian-threepence.com/blog/2012/09/2-struck-on-euro-10c-planchet.html) is struck on an underweight planchet. The planchet was thinner hence the weakness on both sides of the coin.
Have we seen photos in this thread yet?
Quote from: 'purplepennyhunter' pid='4065' dateline='1354082560'This Aussie $2 (http://www.australian-threepence.com/blog/2012/09/2-struck-on-euro-10c-planchet.html) is struck on an underweight planchet. The planchet was thinner hence the weakness on both sides of the coin.
Have we seen photos in this thread yet?
None have graced my "Peeps" in this thread yet
Yeah a pic of the OP's coin would be good.
Here is a picture cropped from a picture I have of it on the scales.
I also measured the diameter today and it matches with a normal coin.
I have also added pictures of the thin coin on the scales, along with a normal coin on the scales.
Thanks for the link PP.
Comparing the $2 to this 50c, there is a much bigger difference in between the weight the $2 coin should be and what it ended up compared to this 50c.
$2 4.1g vs 6.6g = 62%
50c 13.6g vs 15.5g = 88%
I think that being closer to the correct weight than the $2 example might explain why the $2 is a weak strike, while this 50c looks pretty normal.
It's pretty hard to tell form the pics but am I seeing some weakness in the lettering close to the rim. If the coin isn't that far underweight that might be all you'll see.
Weakness will first be found around the edge. Take a look at this NZ error while a different type of error you can see where the weakness is most prominent and where the strength in the strike lies. I guess this would be 50% thickness as it's a split planchet.
(http://www.australian-threepence.com/images/new-zealand-50c-split-planchet-1981.jpg)
More excellent info!
I think there might be a little weakness, but between the wear and tear and a bit of rolling machine damage it its a little hard for me to be sure.
I will take a closer look.
Thanks again.
i thought i had noticed some lighter 50c pieces in my travels but never weighed any to check them, but the did have rims that looked much the same as those here., low almost non existent rims, but still reasonable detail.
could they be a fake?
I think it is unlikely that this (or any other 50c) is fake.
They are not worth enough to bother.
I also think that if someone got the design done well enough that you can not pick it, they would get the thickness right too.
Quote from: 'Ozcoins' pid='4163' dateline='1354244247'I think it is unlikely that this (or any other 50c) is fake.
They are not worth enough to bother.
I also think that if someone got the design done well enough that you can not pick it, they would get the thickness right too.
You may be surprised. I have seen a fake 5c.
Fair enough.
Have you got a pic of the 5c?
I also reembered that I actually have found a fake 1966 50c (a rounded and colored later coin), but that is not white the same thing as making a coin from scratch.