Can mechanical doubling and rotation be related in Lincoln cents?

Olympus620 · August 17, 2025 7:55PM

I have two pennies(just one shown) with a mild rotation from front to back. Both coins also appear to have mechanical doubling. Is there a relationship that would make one error more common if the other error exists? This Lincoln cent is a 1964 and the other is a 1981(not shown).

Morgan White · August 17, 2025 8:14PM

That's actually a good question I think. If the die is rotating, then it's a bit loose and could maybe cause slight bouncing.

I don't know though so some of the experts can chime in.

Olympus620 · August 17, 2025 8:39PM

@4Redisin said:
Mechanical doubling and die rotation are two different things that can both occur to the same coin.

It may just be a coincidence but I asked because of the 4 Lincoln cents I have found with mech. doubling 2 of them also have a slight rotational error. I found the doubling before I noticed the rotation errors.

coinbuf · August 17, 2025 9:01PM

@Olympus620 said:
I have two pennies(just one shown) with a mild rotation from front to back. Both coins also appear to have mechanical doubling. Is there a relationship that would make one error more common if the other error exists? This Lincoln cent is a 1964 and the other is a 1981(not shown).

Mechanical doubling is not an error.

MsMorrisine · August 17, 2025 9:01PM

the dies are installed with one at a different rotation to the other

for mechanical doubling something has to allow the coin to slide across something still

the rotated dies should be installed so the don't move, right? so just because one is rotated wrong means nothing to mechanical doubling

gumby1234 · August 17, 2025 9:16PM

If you have only found 4 Lincoln cents with mechanical doubling you must not have looked at many. A slight rotation of 15 percent or less is not considered an error and it is within tolerance.

Edit I meant to say 15 degrees not 15 percent. Sorry for the mix up.

Olympus620 · August 18, 2025 2:06PM

@gumby1234 said:

If you have only found 4 Lincoln cents with mechanical doubling you must not have looked at many. A slight rotation of 15 percent or less is not considered an error and it is within tolerance.

I have looked for key dates, wheat pennies, silver and obvious errors on pocket change for over 40+ years. I never owned a 30x-60x loop and a microscope until very recently. Some of us are late to the party and still open to learning.

gumby1234 · August 18, 2025 2:08PM

@Olympus620 learning is good.

Old_Collector · August 19, 2025 2:27AM

@Olympus620 said:
@gumby1234 said:

If you have only found 4 Lincoln cents with mechanical doubling you must not have looked at many. A slight rotation of 15 percent or less is not considered an error and it is within tolerance.

I have looked for key dates, wheat pennies, silver and obvious errors on pocket change for over 40+ years. I never owned a 30x-60x loop and a microscope until very recently. Some of us are late to the party and still open to learning.

If you need more the a 10x loupe and do not have visual impairment, then you are doing yourself a disservice. There is no variety or error of real value that requires anything more than that. Those kinds of powers make everything look off.

Remember that minting coins is an industrial scale process and they often push the dies beyond their limits. Also beware the dreaded zinc Lincoln with plating, that creates a lot of additional odd looking stuff.

Your most efficient approach is to know or make a list of the varieties that you seek and look for them. Obvious errors will be, well obvious. Minor errors are generally not worth a premium so don't look for them.

Olympus620 · August 19, 2025 9:25AM

@Old_Collector said:

@Olympus620 said:
@gumby1234 said:

If you have only found 4 Lincoln cents with mechanical doubling you must not have looked at many. A slight rotation of 15 percent or less is not considered an error and it is within tolerance.

I have looked for key dates, wheat pennies, silver and obvious errors on pocket change for over 40+ years. I never owned a 30x-60x loop and a microscope until very recently. Some of us are late to the party and still open to learning.

If you need more the a 10x loupe and do not have visual impairment, then you are doing yourself a disservice. There is no variety or error of real value that requires anything more than that. Those kinds of powers make everything look off.

I agree 100% zoom can make things 'look off' especially near the edges of features however, I am convinced most of it can be attributed to lighting. I also have mild visual impairment which I attribute to years of troubleshooting micro electronics thru microscopes and hobby photography with macro-zoom lenses.

Remember that minting coins is an industrial scale process and they often push the dies beyond their limits. Also beware the dreaded zinc Lincoln with plating, that creates a lot of additional odd looking stuff.

Also 100% true. This probably isn't the oddity you had in mind but I own a 2001s proof Lincoln and some of the lettering shows grey zinc on the edges which to my naked eye looks just like doubling. I know it has limited value.

Your most efficient approach is to know or make a list of the varieties that you seek and look for them. Obvious errors will be, well obvious. Minor errors are generally not worth a premium so don't look for them.

I am not necessarily looking for the most valuable coins. I have conceded I will never locate a DDO 1955 Lincoln in my pocket change but in retirement I have the time to waste trying to find a $10 DDO/DDR variety of which there are plenty. I also rarely purchase coins.
Thanks for your comments.

Can mechanical doubling and rotation be related in Lincoln cents?

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