20 Cent Die Adjustment Strike

Over on our Facebook page we usually put some coin photos up on a Friday afternoon to get our readers relaxing into the weekend. This week, to take the pressure off the working week we’ve decided to focus on striking pressures in particular weakly struck coins. Then we’ll be moving Fridays photos to a more reader friendly Sunday photos (sorry I know it doesn’t have the same ring -name suggestions invited).

For coins to be made the dies need to strike together at force to transfer those designs into the metal blank surface. It takes between 35 and 200 tonnes of pressure to strike coins and this varies with each coin denomination and if it’s a proof coin or a circulation strike. When the press is setup with new dies a touch series is often made increasing the pressure with each coin struck to decide which tonnage will be used in that production run to make the perfect coin and get the most use out of the dies.

Coins struck with a lower than optimal pressure show poor definition and are labelled die adjustment strikes. This can also happen if there is a press malfunction anytime within the production run, a low pressure strike causing weakness in the coin design. This happens uniformly around the obverse and reverse and is generally the same on both sides of the coin.

To give you some idea of striking pressure it takes 35 tonnes of pressure to strike a $2 coin. It takes 140 tonnes of pressure to strike a larger 50 cent coin. The image below is of a touch series of 20 cent pieces with the weaker strikes (5 tonnes) top left increasing to the stronger strikes (120 tonnes) bottom right.

20 Cent Touch Series. Approx 5 tonnes top left to 120 tonnes bottom right

In 2015 the Royal Australian Mint produced a number of collector 20 cent coins that were available to buy when you purchased a newspaper. Collector interest has always been with the limited release red coloured poppy dollar coin issued with the set. But for those with packyboxitis* and an interest in errors here are a couple of mistakes that you need to look out for.

Coin Packaging Error

Recently a collector contacted us about an anomaly in the packaging of one of the 20c coins in the set. Their Royal Australian Navy 20 cent has been sealed into the packaging the wrong way around. It has the Queen’s head or obverse side facing out (see above) and as a result you cannot actually see which coin the packaging holds.

Another error is the wrong coin type in the labelled packaging. The coin pictured below (top) is a Royal Australian Navy coin in the wrong Mateship packaging. The coin below (bottom) is how this packaging should actually appear.

We call this a packaging error as there is nothing specifically wrong with the coin. Of course one must take due care and inspect the packaging closely to see if there is any evidence of tampering if identifying this kind of error.

2015 ANZACS Remembered Packaging Error

There have been a number of packaging errors made at the Mint over the years, a few which appear in the coin catalogues. Probably the most notable is the 1986 mint set with the 1985 dated 10c piece.

Thanks to the coin owners and Blog readers for permission to share.

*packyboxitis is a made up name used in the collecting world for collectors that obtain items because of the way they are packaged. For example the same coin in its packaging might be in a collection twice because it was issued in different packaging.

If you haven’t checked out eBay for a while then you’re missing some impressive and quality error coins currently selling on that great online garage sale. Even if you’re just a window shopper you should still take a look as these kinds of error coins aren’t seen often.

2016 20 Cent Struck on a Dollar Planchet

Wrong planchet coin errors are not always dramatic to look at but they are when they are struck on the wrong composition planchet. This 20 cent doesn’t appear to have been struck on a cupro-nickel planchet but an aluminium bronze planchet which the seller claims is for a one dollar coin so presumably weighs 9 grams and not 11.31 grams as a 20c should.

2016 20 Cent Struck on a Dollar Planchet

2000 20 Cent Struck on 10 Cent Planchet PCGS MS64

A stunning lustrous choice uncirculated example of a wrong planchet error. A ten cent coin blank was accidently struck with 20 cent dies and the resulting underweight 20c has been graded by PCGS as MS64 (83914942). A superb error coin with the added assurance of the PCGS slab. This should give buyers confidence to bid on this error coin for sale.

2000 20 Cent Struck on 10 Cent Planchet PCGS MS64

1994 10 Cent Struck on 5 cent Planchet PCGS MS65

Here we have another wrong planchet similar to the above example, this time an earlier date with the Raphael Maklouf portrait of QEII. This coin graded MS65 (83914941) at PCGS the equivalent to gem uncirculated for those who use adjectival grading terms. If you like a top grade error coin then you should have confidence in this seller.

View on eBay- 1994 10 Cent Struck on 5 cent Planchet PCGS MS65

2016 Decimal Changeover Anniversary Dollar Die Cap Pair

I am amazed at how this error pair left the Mint. What we have in this listing is a matched pair of die caps from the top and bottom dies (hammer and anvil) each planchet having stuck to the dies and struck multiple brockage coins before falling away (at the same time) or the press being stopped and the die caps being forceably removed. In this case the hammer (top) die had to be the more bottle cap shaped obverse and the anvil (bottom) die the reverse 5 kangaroo design. The opposing sides of each coin is flattened (later state) indicating it struck many brockage coins. This commemorative design is a low mintage issue and this error pair so outstanding I might well have to sell a kidney to buy it.

View on eBay- 2016 Decimal Changeover Anniversary Dollar Die Cap Pair

2014 20 Cent Off-Centre Double Strike

Second chance offering with its original buyer failing to complete the transaction, this means it’s back to the bidding with this double struck platypus 20 cent in a new auction. High grade and two visible dates this is a highly desirable error coin. In the case of this double struck coin, the second strike is about 85% off centre.

View on eBay- 2014 20 Cent Off-Centre Double Strike

1974 10 Cent Flipover Double Strike-Indent PCGS MS64

As the seller suggests it is “rare to find” this error, it would certainly be rejected by the mint roll machine! A very nice example for sale on the ‘bay graded by PCGS as MS64 (30336010). Take a look at our flipover double strike article to see another example (the same date too), read about how this occurred and see what the matching coin of this kind of error pair would look like.

View on eBay- 1974 10 Cent Flipover Double Strike-Indent PCGS MS64

1925 Threepence Variety

The 1925 Australian threepence showcased in this article is much more than your everyday pre-decimal small silver threepenny bit. To variety and error collectors this coin is an interesting study piece so let’s look more closely at its’ features. Evident on this coin is significant die cracking and heavy die clash. Let’s first look at the cracks and broken die. Click on any image to enlarge.

Reverse Die Break and Cracks
As more coins are struck, often through overuse the dies will often crack. This leads them to either shatter or be retired. Evidence of the cracking is always apparent on the struck coin and if a piece of die breaks away then it will leave a cud formed on the coin. In this case the crack has extended from the rim beads through the date and up to the scroll. It has lead to a piece of the die breaking away in the middle of the 5 leaving a cud. We’ll call this (just as in the filled 8 1948 threepence) the filled 5 variety.

1925 Threepence Filled 5 Die Crack

This coin also exhibits a large die crack from the rim to the kangaroo. There is also minor cracking through the legends.

1925 Threepence Die Crack Kangaroo to Rim

Die Clash
This occurs when the obverse and reverse dies hit together at force without a planchet in between them. This leaves the impression of the other die on the surface most of the time visible in the open fields of the coin. We’ve circled and numbered each part of the coin to explain the incuse markings. Our obverse image below shows each point circled (left) and an inverted overlayed reverse (right) showing the details of the clash so you can understand it a little easier.

1925 Threepence Obverse. Right with overlayed inverted reverse to explain die clash

Obverse
1. Looks like George V is smoking! It is in fact the emu’s front leg that’s up holding the shield.
2. The kangaroos front leg, paw, and the edge of the shield can be seen behind KG’s head.
3. The bottom of the scroll can be seen below the back of the King’s coat.
4. The letters of the date 2 and 5 can be seen inverted, these are easily made out in the fields below the portrait.

Reverse
5. The incuse curve on the reverse between the date and the scroll is the bottom edge of the King’s portrait.

1925 Threepence Variety -Circled Die Clash