Machine doubling vs a true double die

I know there's a difference but what is the difference between a "true" double die vs those that are "machine" double die?

 

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Did you do a search of coin talk first before posting? It's been covered in great detail and Doug has resources on this within the resources system.

Ruben

 

Big difference A true DD is worth a lot more, while machine doubling is usually common As Ruben said, search the forum, you'll find many topics on this.

 

A true doubled die is doubling on the original die due to various situations in it's being made ( this determines the type of DD) and then this doubled impression is struck on the planchets producing true doubled died coins.

Machine ( strike, mechanical, etc) doubling coinage is produced from a NON-doubled die by the normal die rotating or moving slightly due to a mechanical problem during the striking process, producing a "shearing" flatter type of doubling effect.

This is a general description, not inclusive. Read this URL for different types of doubling effect and photos.
http://koinpro.tripod.com/Articles/OtherFormsOfDoubling.htm

Jim

 

http://www.cointalk.com/forum/t13902/

 

I didn't originally search the forums. Did you know there are over 15 pages of threads containing "double die"! Most of them are about a specific coin. I looked at the 1st 6 pages & found one but due to the way they typed it I can't read it.

The link helped a lot as I was just looking for a simple explanation although I know it's hard to do that.

So lets see if I'm understanding this correct.
If it has a shelf like appearance like in 1999 P Connecticut Quarter, Double Strike?
It's machine but if it's like this attached picture of the 1955 it's considered a true double die right?

 

I threw up a bunch of threads dealing with DDO's and Ikes. Look through the latest threads.

 

BTW - it is not a simple thing. Machine doubling and DD's are hard to distinguish until you learn to see enough of them

 

http://www.coinbidders.com/Strike Doubling Flyer - PDF.pdf

 

Usually shelf like. Sometimes the machine doubling effect can produce "scoop" like effects which they say is from the ejection process. But sometimes it is almost impossible to tell from photos.

here is a close up of the date on my 55 DDO. Notice how the numbers look like they are "blended" as they are at same height. On DD that are not so separated, this will just look like a line along the top or near the top of the number or letter. This often produces the separation at the ends of the number, producing the "notching" that is a characteristic.



Here is a hard one for most: It has multiple "scoops" which I believe is from the ejection, but it is not a doubled or even tripled die. So it is not always easy to tell. Especially from photos. But it was exciting for me to find!




Jim

 

Cool!!:thumb:

 

Ok, I knew it wouldn't be easy & that there are varieties & some disputes but wow I didn't know it would be so technical.

Thanks!

 

Here is an example of a doubled die and strike doubling (I prefer to use the term MDD, machine damaged doubling, instead of strike doubling), on the same coin. Maybe it will be easier for someone to see the difference between the two when they are right next to each other. This is from a 50c 69D DDR-009.

Larry Nienaber

 

Oh thanks!

 

It looks like the area inside the A would be MD, but all else looks like DD. Is that what your picture shows?

 

Here are a few Reverse Examples to look at. The machine doubled devices always appear pushed/distorted/mangled and not a true doubling on the die. Normal die just the striking method is distorted.
Memorial:
http://imgs.inkfrog.com/pix/coop49/Memorial_Machine_Doubling_01.jpg
http://imgs.inkfrog.com/pix/coop49/Machine_Double_Cents.jpg
http://imgs.inkfrog.com/pix/coop49/Machine_Doubling_05.jpg
http://imgs.inkfrog.com/pix/coop49/Machine_Doubling_More.jpg
http://imgs.inkfrog.com/pix/coop49/Machine_Doubling_More_01.jpg
http://imgs.inkfrog.com/pix/coop49/Machine_Doubling_Date_and_MM_or_other_devices.jpg
http://imgs.inkfrog.com/pix/coop49/Machine_Doubling_Proof_Coins.jpg
Wheat Reverse:
http://imgs.inkfrog.com/pix/coop49/Wheat_Cent_Machine_Doubling_01.jpg

 

Thanks for the flyer it is very informative. I took the 10 picture test and got them all correct thanks to the numerous post with photos I have read on CT.

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I'm sure I've messed up this reply and I'm new to coin collecting however I have a 1965 Washington quarter with the same kind of shadowing of letters on the in God we trust....would u look and we if you agree and if this is something worth keeping..thank you