Machine Doubling is caused by the machine. A doubled die coin was struck from a die with hub doubling created on the die. Machine Doubling can be seen on a doubled die, but Machine Doubling never created a doubled die? Why Not? Because a doubled die coin, is created by a doubled die.
here is an:

Note the top image: This is what a normal coin would look like that year.
Note the second image, this is what a DDO would look like that year. Note the devices are larger sized, showing spread on the devices?
Note the third image. It is from a normal die, but shows Machine Doubling. Note these devices? Note the contour of the devices are reduced on one side of the coin. The other sides of the devices are normal. This is what you are seeing on your coin on the reverse. On side of the devices are normal and the other side has Machine Doubling present. I mentioned above, that Machine Doubling never creates a doubled die. Only a doubled die creates a doubled die. So on to the next image:

Note all 4 images are a doubled die on the dates? Now note the yellow arrows ? This is Machine Doubling on a doubled die. Note it affects the date and the mintmark. A general rule is that on a doubled die on the pre 1990 coins, if you see Machine Doubling on the date and the mintmark, that is Machine Doubling. So this is a doubled die (on the date) and Machine Doubling on the date and the mintmarks. The 1968-1972 coins had a lot of Machine Doubling present.
Let's review with my opening statement:
So if the devices are showing a reduction of size, (not spread) it is Machine Doubling. Hope this helps?
CoopHome: Why is Machine Doubling, never a doubled die?
here is an:

Note the top image: This is what a normal coin would look like that year.
Note the second image, this is what a DDO would look like that year. Note the devices are larger sized, showing spread on the devices?
Note the third image. It is from a normal die, but shows Machine Doubling. Note these devices? Note the contour of the devices are reduced on one side of the coin. The other sides of the devices are normal. This is what you are seeing on your coin on the reverse. On side of the devices are normal and the other side has Machine Doubling present. I mentioned above, that Machine Doubling never creates a doubled die. Only a doubled die creates a doubled die. So on to the next image:

Note all 4 images are a doubled die on the dates? Now note the yellow arrows ? This is Machine Doubling on a doubled die. Note it affects the date and the mintmark. A general rule is that on a doubled die on the pre 1990 coins, if you see Machine Doubling on the date and the mintmark, that is Machine Doubling. So this is a doubled die (on the date) and Machine Doubling on the date and the mintmarks. The 1968-1972 coins had a lot of Machine Doubling present.
Let's review with my opening statement:
Quote:
Machine doubling is caused by the machine. A doubled die coin was struck from a die with hub doubling created on the die. Machine doubling can be seen on a doubled die, but Machine Doubling never created a doubled die? Why Not? Because a doubled die coin, is created by a doubled die.
Machine doubling is caused by the machine. A doubled die coin was struck from a die with hub doubling created on the die. Machine doubling can be seen on a doubled die, but Machine Doubling never created a doubled die? Why Not? Because a doubled die coin, is created by a doubled die.
So if the devices are showing a reduction of size, (not spread) it is Machine Doubling. Hope this helps?
CoopHome: Why is Machine Doubling, never a doubled die?


















