What Is The Difference: Uncentered, Partial Collar, Broadstruck Ect ...

This is a great site full of info http://www.error-ref.com/
John1

I'll post to some examples in threads here on CCF.

Uncentred: That's just bad English. It should be "off-centre".

Off-centre: The coin blank is seated properly in the collar, but both dies are misaligned (if only one die is misaligned, then the term for the error is "misaligned die" rather than "off-centre"). The coin's edge should appear more or less normal. An alternative way to make an off-centre coin is similar to a broadstrike (i.e. the collar is completely missing) except the coin is nowhere near centrally struck. Most of the extreme "off-centre" coins are of this type.

Partial collar: The coin blank has not quite seated properly in the collar; it's "popped out" before the coin is struck. The dies are all properly aligned, but the coin blank is not, resulting in slight off-centring and some of the edge being squeezed out between the dies and the collar. If it goes most of the way around the coin, it's known as a "railroad rim", because it resembles a railway wheel.

Broadstrike: the collar is completely missing (either broken away or not installed properly). The coin is struck between the two dies, but there is no collar to stop the metal squirting out between the dies and spreading out. The coin's normal edge (reeding, etc) will be completely absent; instead, it will have a wide rim of splayed metal all around.

A broadstruck coin can look similar to a coin that's been removed from one of those "lucky penny" ring-holders, or some similar circular mounting arrangement (which would be post-mint damage and not a mint error). The difference is in the thickness of the splayed metal: on a broadstrike, the metal ring is quite thick - usually thicker than the actual coin. A removed-from-ring-mount coin has the surrounding ring of metal that's much thinner than the rest of the coin.

I agree,the old School Dealers from the 1950/60's and even the 1970's would be turning over in their graves with what the later 'self appointed' Australian Coin experts have gotten away with in print over the last 40 years.
Its starting to level out again since the Internet started ,peoples opinions and views are under more scrutiny as published material from post WW11 is slowly appearing on the Web.for anyone to source.

I'll admit to being a literalist: an off-centre coin is off-centre, whether it's got parts of the design missing or not, and I don't see the need to make up a brand new word to describe a coin with an unfashionably small amount of off-centring. However, I would agree that for it to have any significant collector's premium, an off-centre coin should indeed have parts of the design missing. The "perfect off-centring" would be a coin which is so far off-centre that it has major components of the design missing, but not the date, mintmark or other features necessary for a full attribution of the coin.

As for the coin in the above post, I would say it has a slight partial collar (quite common in a coin as small and thick as the $2), or perhaps very slight off-centring; it's hard to say without seeing the entire coin (both sides). A similar effect can be created by squeezing coins in a vise, so I'd also want to see no evidence of this. Finally, many counterfeit $2 coins show this kind of feature, as a result of being rammed through a ring die. Be prepared to hear that possible answer as well.

Yes, a very, very mild partial collar. GIven the natire of the $2 coin and the resultant commonness of this particular error, I'd consider it more an "error in design" rather than a striking error - kind of like ghosting on some of the old predecimal pennies.

The Topic for discussion at the last meeting of the Queensland Numismatic Society was "Errors and Varieties". Going through my notes, I've noticed that the old-timer collectors tend to use the general term "mis-strike" to describe any of the errors mentioned in this thread: off-centre, broadstruck, misaligned die and partial collar.