coins minted on the "wrong" blank

[Komisaruk 1]

In the March LCA catalogue, there are a number of coins that have been minted using the "wrong" blank. This may be a flan that is thinner or thicker than usual, or one made of a different metal. Some look like they were mistakes (or the mint workers were mucking about!), while others look like they were for a special edition.  For example, some normally bronze pennies have been struck on cupro-nickel, either apparently mistakenly (Lot 2495 ) or intentionally (Lot 2406 ).  Can anyone suggest (i) why mis-strikes on the wrong flan might occur and how rare they are, and (ii) what was the purpose of intentionally striking a coin on  the "wrong" blank (e.g. the case of Lot 2406 - 1868 proof penny in cupro-nickel)?

[Colin G. 147]

There are as you say very different reasons behind such coins. The majority would be errors caused at the mint when a planchet (blank coin) has accidentally got mixed in with another batch of planchets for a different coin. For example if a two pence blank got mixed into the blanks for the 10 pence coins the result would be a 10p coin but with the colour appearance of a two pence. As for rarity it really does depend, most would be fairly limited in numbers and some may even be unique, but they are strictly error coins and therefore tend to be collected by error collectors.

I suppose you could also theoretically get mint workers playing silly sods and dropping a few different planchets into the batch.

 

Whereas it is not unusual for specific coins to be struck on a blank of a different material intentionally. This may have been for release as part of a set, such as the silver 10p and 1p pieces, for VIP's or it could have just been an attempt to try a strike on a different material to look at other material options for striking. Such examples are usually recorded when issued and therefore it can often be determined that they were intentionally struck rather than an error.

A simplified explanation but hopefully it may answer some of your questions.

[Rob 3,152]

The 1967 off-metals are probably the mint workers having a bit of fun as this coincided with the closure of the mint at Tower Hill and its relocation to Llantrisant. There are quite a few of them about.

The 1868 cupro-nickel proofs were intentional as all denominations otherwise struck in bronze are known and it coincided with the introduction of cupro-nickel coins for Jamaica. Copper and bronze don't perform well in humid tropical conditions, so they switched to cupro-nickel for this reason. The same applied to a number of British possessions with similar climates.

For example, here is a third farthing struck in cupro-nickel from the same period.

[mrbadexample 1,006]

11 minutes ago, Rob said:

For example, here is a third farthing struck in cupro-nickel from the same period.

I covet it. 

[copper123 1,485]

If I remember rightly the 1868 proofs were issued in a set  third farthing , farthing ,halfpenny and penny  or was that the 1877 bronze set ?

I am sure someone out there knows

 

[Rob 3,152]

1 minute ago, copper123 said:

If I remember rightly the 1868 proofs were issued in a set  third farthing , farthing ,halfpenny and penny  or was that the 1877 bronze set ?

I am sure someone out there knows

 

And there were quarter and half farthings dated 1868 as well, but these in the same design as the early Victorian coppers. I don't think they were made as sets because the halfpennies appear more often than the other denominations, certainly more so than the pennies. Maybe there were sets made and a few extra halfpennies. Having said that, I've never seen a boxed set, nor an empty box to take them.

[VickySilver 830]

Yes, I have quite a few intentional and unintentional OMS (off metal strikes). The mint not only took 1967 liberally, but actually nearly all of the earlier 60s as well with 63-66 era also with many OMS.

My favorite is either Secret Santa's 19KN penny or the 1920 specimen matte half penny from Nicholson.

[Colin G. 147]

22 minutes ago, VickySilver said:

OMS (off metal strikes).

Vicky keep going with the terminology, I am sure I will start to use it one day.....enough repetition and it should start to sink in 

[VickySilver 830]

You're getting sleepy.....

 

LOL

[Gary D 76]

As you can see my avatar is a 3d minted on a Nickel blank. Peck records this as Nickel thin flan No 2171 possibly unique, never did find out what happened to Pecks as it was from his own collection and not in the British Museum. The Irish 6d was on Nickel at the time so obviously a 6d blank getting in with the Brass 3d's.

Edited February 26, 2016 by Gary D

[VickySilver 830]

Ah yes, tried to get that off you! LOL

I like the 1946 OMS trial strikes in copper nickel but can't seem to find even record of the florin and halfcrown. Anybody? Rob?

[Rob 3,152]

1 hour ago, VickySilver said:

Ah yes, tried to get that off you! LOL

I like the 1946 OMS trial strikes in copper nickel but can't seem to find even record of the florin and halfcrown. Anybody? Rob?

Nope