Technical deffinition of a double die?

Raybo

I would not know one if it hit me in the face.

Some images of a true DD as opposed to machine doubling would be appreciated.

Thanks again,
Ray

cladking

Most are the result of a change in the orietation of the die or hub between hubbings.

Dies are (were) imprinted multiple times by being forced against a mirror image hub
to bring up all the details.

leothelyon

<< <i>Most are the result of a change in the orietation of the die or hub between hubbings.

Dies are (were) imprinted multiple times by being forced against a mirror image hub
to bring up all the details. >>



And they could have been retooled.


Leo

IGWT

how 'bout a couple tripled die obverses, instead?

ProofArtworkonCircs

<<Technical deffinition of a double die?>>

Step 1 - I think you mean "doubled die".

I am real partial to class III DD where two slightly different designs are used in the multiple (no longer used) hubbing steps.

Raybo

I have an example.
I see doubing on this coin and i'm guessing it's just machine doubling.



Now how the heck would I be able to pick out a true DD?

50cents

Link to a great website on doubling Link

19Lyds

Machine Doubling:



Doubled Die:



Notice on the Doubled Die that there is clear separation between the letters whereas on the Machine doubling there is not. The machine doubling also appears flat and shelf-like. This is caused from slight movement of the hammer die as it is lifting from coin just after minting or from the coin being ejected before the hammer die has completely lifted.

howards

The original question was "technical definition of a double (sic) die". As someone previously noted, the correct terminology is "doubled die".

The definition is pretty easy. A doubled die is a coin on which the coin's devices (the image) are doubled. Thus every coin struck from that die will show the doubling. The doubled (or tripled in the case of what IGWT presented) images on the die result in one of two ways:

1) Historical doubled dies result because the die is created by pushing it under high pressure against a positive image called a hub. This process had to be repeated multiple times to bring up the image on the die. If the alignment wasn't perfect, then a doubled die resulted.

2. Modern (single-squeeze) doubled dies are a little controversial. They are thought to result from the hub/die twisting with respect to each other during the single-squeeze hubbing. It cannot be an alignment problem, because the dies aren't hubbed multiple times any more.

Recognizing die doubling from other forms of doubling can be more difficult than understanding the definition. Generally, die doubling shows up as splits with a 3D look to the doubling. Strike doubling shows up as low, flat to the field, and one dimensional. There is a good chapter in the back of Cherrypickers' Guide on this subject. Also, see the following articles:

http://www.shieldnickels.net/articles/Stanton_DieDoubling.pdf

http://www.shieldnickels.net/articles/Stanton-DoubledDies/DoubledDies-Stanton.html

InternetJunky

<< <i>Machine Doubling:



Doubled Die:



Notice on the Doubled Die that there is clear separation between the letters whereas on the Machine doubling there is not. The machine doubling also appears flat and shelf-like. This is caused from slight movement of the hammer die as it is lifting from coin just after minting or from the coin being ejected before the hammer die has completely lifted. >>



I'm with Raybo on trying to figure out the difference, and thanks for this example. So I'm wondering it must be near impossible to find doubling on a worn coin then correct? Because with the wear the doubling on the letters would pretty much blend together? Just curious, I'm cherrypicking tons of Lincolns right now and have come across a lot of interesting stuff, and also I'm sure a lot of machine doubling based on those pictures .

Raybo

So the devices should look the same?
Same as in "the same "?

Raybo

The "classic"

I just don't get why the whole design is not doubled.

droopyd

<< <i>The "classic"

I just don't get why the whole design is not doubled.

>>



In the case of the 1955DDO Lincoln, the die rotated slightly around a central point. Notice that there is far more separation between the "L" in Liberty than there is in the "Y".

GrumpyEd

Also if you look close on a 55 DDO there's some doubling in the bust. Look close at Abes mouth or the lower part of his nose.

frnklnlvr

Here are some pics of a 1956 50c DDR FS-801.

On EPU, the doubling shows as extra thickness. On USA, you can see the notches at the bottom of the letters.




The eagle is from a 1959 50c DDR FS-801. This is class III 'design hub doubling' that ProofArtworkonCircs was referring to.

Steve27

"double(d) die
A die that has been struck more than once by a hub in misaligned positions, resulting in doubling of design elements. Before the introduction of hubbing, the individual elements of a coin's design were either engraved or punched into the die, so any doubling was limited to a specific element. With hubbed dies, multiple impressions are needed from the hub to make a single die with adequate detail. When shifting occurs in the alignment between the hub and the die, the die ends up with some of its features doubled – then imparts this doubling to every coin it strikes. The coins struck from such dies are called doubled-die errors – the most famous being the 1955 Doubled Die Lincoln cent. PCGS uses doubled die as the designation."

GFourDriver

The easiest way for me to recognize a true doubled die is the notching in the letter serifs. If you see notches in the serifs, you know you have true doubling.

itsnotjustme

I'm in the can't tell crowd. Some of those coins posted, I just don't see it.

HighRelief

Vam-3 (Shifted Eagle) This is the strongest doubled reverse die of the Morgan series and shows prounounced doubling of the bottom of the eagle's wings and tail feathers, olive branch and arrow shafts.
The doubling was caused by a misalignment between the hub and die in one of the early blows.

19Lyds

<< <i>I'm with Raybo on trying to figure out the difference, and thanks for this example. So I'm wondering it must be near impossible to find doubling on a worn coin then correct? Because with the wear the doubling on the letters would pretty much blend together? Just curious, I'm cherrypicking tons of Lincolns right now and have come across a lot of interesting stuff, and also I'm sure a lot of machine doubling based on those pictures . >>

Not difficult at all, you just have to know what you are looking for.

As for Raybo wondering about the 55/55, just look closely at the photo below and study the nose, eye, ear and lips.



Also note that Abe's lapel has clear doubling.

Too often folks only concentrate on the obvious which enables them to overlook a lot of significant details.

TwoSides2aCoin

Dear Ray,

I keep it simple. "Notch or Naught".


Joe

TwoSides2aCoin

If not, it's naught. If notched, it is.

cladking

Here's another way to tell that can be conclusive in most cases.

Look at the tops of the letters or numbers in the secondary image. The primary image
tops will be gently rounded in cross section (on good strikes). If the secondary image
shows this rounding on top then it's a true doubled die. If it shows a flat surface then
it's most probably shelf doubling. If you see small scratches on the seciondary images
radial to the primary then it's most assuredly shelf doubling.

There will be a few pictures that can be tough to tell and even coins in hand can throw
you on rare occasion. Keep looking at them and you'll get better.

RBinTex

I think you mean DOUBLED Die.

fcloud

Double dies don't have flat shelves, but have distinct doubling. The best way to see it is on the point of letters or number. The serif on the 1 and the base of this 9 are very easy to see.

frnklnlvr

I think we all started where you are not knowing how to tell the difference. I just had to keep studying coins that I knew were true doubled dies until I could tell the difference.