1956 Thin Flan Thruppence, not Gurnsey

[DrP]

Hi there, my friend asked me to check out his 1956 3d coin that has a really thin flan. I looked this up but could only find the thin flan 3d from Gurnsey from 1956. His coin is not the Guernsey one but looks like the normal 1956 3d brass coin but with a thin flan. Anyone seen this coin before?   

Maybe I didn't search hard enough But all I could find reference to was the Gurnsey variety.

Thanks in advance for any information.

DrP

[1887jubilee]

Interesting. I had never come across other thin flan 3ds. I have a very thin 1944 3d. The normal 3d is 2.69-2.72mm with a vernier caliper. The thin 3d is 2.14-2.16mm.How thin is the  1956?

[DrP]

I'll have to check as he has it back. I think its a little thinner still.

[Martinminerva]

Would need to see a picture. An awful lot of so called "thin flan" 20thC coinage is post mint damage/tampering as the coins have been submerged in acid either deliberately or else in acidic soil conditions before being discovered as detector finds. I myself have unearthed many such pieces. The giveaway signs are that the surfaces are mottled, stippled or porous where the acid has eaten away constituent parts of the metal alloy.  If the surfaces are anything different from a normal circulation piece, then I would fear that is what you have...

[VickySilver]

Indeed, as have I. However, the mint did "flub" on occasion and struck coins on thinner planchets.  I bought a bunch of them as a lot from London Coins about 10 years ago. Have a few others and thrown in were some off metal strikes and off center, etc.

[DrP]

OK, this one is just unser 2mm. It doesn't look like damage. I'll try to get pics.

Possible it could be a magicians gimmick coin? One that fits inside another coin or something. It's size is that of a normal 3d though, just under 2 mm thick.

[copper123]

The royal mint produced many coins for other countries could it be a foreign flan that mistakenly got fed into a domestic brass threepence batch - there is a similar sized coin of canada I think or it could be from many other african countries as well more likely commonwealth countries than not