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Varieties & errors1955 double die penny: real vs machine doubling
In short
- A doubled die is a mistake made while the die itself was being made, so coins from that die share the doubled design. Its strength and appearance vary by variety and wear.
- Machine doubling happens while a coin is being struck. It often looks flat, like a little shelf, and usually adds no collector premium.
- The 1955 Doubled Die is the most famous doubled die penny. Many fakes exist, so a possible one needs authentication.
How a die gets doubled
The Mint makes coin dies with a hub, a steel tool that carries the raised design. The hub is pressed into a blank die to copy the design onto it. Historically, multiple hub impressions were often needed. If the hub and die didn't line up exactly between presses, the die ended up with two slightly offset copies of the design.
Every coin struck from that die carries the same doubling. That's why doubled dies are collected as varieties. Modern single-squeeze die production can also produce doubled dies; the manufacturing change did not eliminate every form of doubling.
Common clues on strong doubled dies
- Two clear, complete outlines of the same letters or numbers.
- Both outlines are rounded and raised, with a visible split between them. The ends of the letters (the serifs) look split too.
- It shows in the same places on every coin from that die.
What machine doubling looks like
Machine doubling, also called strike or shelf doubling, happens when the die bounces or shifts slightly as it strikes the coin. It pushes the edge of a letter sideways and leaves a flat, step-like shelf next to it. There's no split between the two outlines. It looks different from coin to coin, and collectors treat it as a curiosity, not a variety.
Die deterioration doubling
As a die wears out, its design can blur and spread, and parts of it may look doubled. A well-known example is the so-called "Poor Man's Doubled Die" 1955 penny. It is much more common than the real thing and sells for little.
The 1955 Doubled Die
In 1955, one front die at the Philadelphia Mint was hubbed out of line. The strongest doubling is on the date and the lettering, LIBERTY and IN GOD WE TRUST. Lincoln's portrait shows very little. There is no mint mark. NGC describes roughly 20,000 to 24,000 examples entering circulation 1955 Doubled Die Obverse.
For a genuine G-4 example, our catalogue estimate is $580. A normal 1955 penny 1955 is common. Actual prices depend on condition and attribution; an estimate is not a purchase offer.
Why close-ups matter
Doubling is small. One blurry photo can make machine doubling look real, or hide the real thing. Take sharp, well-lit close-ups of the date and of LIBERTY. These images can support an initial assessment in Penny Value; the app does not authenticate a variety.
Check yours
Take sharp close-ups of the date and lettering for an initial comparison. Have a possible major variety examined independently.
Check your own pennyPenny Value is an Android app for now, so it isn't on the App Store. The values and checks on this page are free to use.Penny Value is an Android app. Open this page on your Android phone to check your own penny with a photo.
Coins in this guide
- 1955 Doubled Die ObversePhiladelphia · Roughly 20,000-24,000 are thought to exist; perhaps about 40,000 were struck during one night shift. Part of the 330,580,000 1955 total.$980worn$1,700MS-60
- 1955Philadelphia · Part of the 330,580,000 1955 cents; about 20,000-24,000 of those are the doubled die.7.5¢worn$1.50MS-60
Related guides
Sources
- Wikipedia, “Doubled die” (accessed 2026-09-26)
- Wikipedia, “1955 doubled die cent” (accessed 2026-09-26)
- NGC, “Double Dies vs. Machine Doubling” (accessed 2026-10-05)
- NGC, “Counterfeit Detection: Altered 1955 Doubled Die Obverse Cent” (accessed 2026-10-05)