DD versus Machine Doubling

Whitby

OK, can someone please provide an explanation of the difference between machine doubling and a true DD?

I have no clear idea and I look forward to the replies...

ahooka454

a true dbl die is easy to see once you know what to look for. Machine dbling is striking error. no big deal. a dbl die is doubling on the die not the coin. just look at some photos and you will see what the difference is.... sorry i dont have any right now. someone here will

Paultjuno

Back to top .... just curious as I also would like a better explanation. I've never quite understood. How does doubling on the die occur in the first place, seems qa should spot these before it ever becomes an issue.

TAClough

Look at the profile of this coin, you will notice machine doubling of the profile and some of the letters (shelf like appearance).




Now look at the following pictures, you will notice a ridge between the letters.




Hope this helps.

MrSpud

A true double die is where the actual die that stamps the coins was accidently impressed with a doubled image, whereas machine doubling has a die with no doubling but the planchet moves as the coin is being stamped and some of the coin looks similar to a doubled die coin. The typical pickup point for a true doebled die is split serifs on the letters and no doubling of the mintmark on older coins. The typical description of machine doubling is a shelf like appearance to the doubling with no clear splits on the serifs of the letters.

Type2

DDO not machine. Machine on bottom

TexasNationals

On a doubled die, doubling (almost always, exception 1909 DDO) will be rounded and show extra thickness or serifs and rounded if there is a break in doubling. Mechanical doubling, or strike doubling (aka double die, note double not doubled) will be flat and shelf like doubling. Also the MM is usually affected ant this is a telltale sign of strike doubling before the 1990's when the MM was put into the master hub so it will show doubling also.

TexasNationals

Type 2 shows it great, rounded doubling on the DDO and flat shelf like doubling on the machine doubled coin.

good job type 2

dbldie55

JT Stanton wrote a great piece on it. You can access it here.

mgoodm3

jfoot13

cherry pickers guide has a nice section on all the classes of DD and the difference between them and machine doubling and pics... even a little quiz at the end to see how well you learned your lesson... a lot of information and will point you in the right direction..... great investment

ProofArtworkonCircs

Note for Paultjuno
There are cases where the mint knew they had a doubled die and tried to buff the evidence off and then used the die and even pulled ithem and buffed them a second time.

coinsarefun

This link was very helpful to me
Hope it helps you out.

Educational Series on Die Doubling

Frankcoins

<< <i>Note for Paultjuno
There are cases where the mint knew they had a doubled die and tried to buff the evidence off and then used the die and even pulled ithem and buffed them a second time. >>



What are some examples of this?

ProofArtworkonCircs

Here is yet another source of information on doubled dies by Mr. Stanton again.
http://www.coin-gallery.com/cgstanton3.htm