I have seen the above website before. Maybe I didn't make myself clear. I understand how the double die works. What I do not understand is, in a STRIKE DOUBLING, how only a small part of a coin is affected. It would seem that any design on the coin as high as the doubled part should also have been affected.
I've found the same strike doubling If it helps any, I recently found what looks to be exactly the same doubling on a 1970-S cent. I wonder how many of these are around....? Just how common is strike doubling, and why wouldn't it also be collectable? AJ
I wouldn't do that if I were you...ebay could kick you off for false listing...if the coin is not a error I wouldn't list it as an error. Speedy
It is strike doubling (a.k.a., machine doubling, machine damage doubling, machine doubling damage, mechanical doubling, ejection doubling, etc.). It most often affects the date and mintmark in Lincoln cents, but other areas can be affected. I've never quite understood how or why it is often so localized. You do sometimes find more severe cases in which the doubling is more widely distributed. Strike doubling is generally attributed to a bounce, shift, or twist of the die immediately after the initial impact. The secondary movement pushes down or pushes to the side already-struck design features. Flat shelving of the affected design elements is characteristic. Interior design features may not show shelving.
It is my opinion -- one that is shared by many others -- that strike doubling IS a minting error. After all, it is related to the downstroke of the hammer die. It can sometimes be so severe that you end up with distinctly duplicated and well-separated design elements. To dismiss it as damage is, I think, a form of special pleading. Alan Herbert considers it "damage", but I respectfully differ in my assessment. I am happy to pay, and have paid, as much as $75 for extreme cases of strike doubling. Heavily doubled Sac dollars have sold on eBay for well over $100 (which I think is excessive). That being said, most cases of strike doubling are trivial and have little collector value.
My theory is the middle of the coin doesn't move as much as the outside, just like a car tire. I'm sure it takes the slightest budge on the outside of the coin to cause the doubling. Maybe the side where the date is moved the slighest bit to the right and caused the doubled date. The other part of the coin might not have moved, or at least not as much. This is how I think it happens.