Every so often a coin is struck on a planchet whose specifications
deviate markedly from those of a normal coin. A small minority turn
out to be legitimate test planchets while the rest have more prosaic
explanations. The trick is to discriminate between these two
possibilities and resist the temptation to choose the most exotic (and
Shown here is a 1944 Lincoln cent that weighs between 4.1 and 4.2
grams. Normal copper-alloy cents weigh 3.11 grams.
For decades, these hefty 1944 cents were identified as having been
struck on experimental planchets. Overweight 1944 5-cent coins
received the same treatment. Nowadays both populations are widely
considered by the entire numismatic community to be Mint errors,
although the cent is still listed, with reluctance, at uspatterns.com
as P2078. The overweight cents and 5-cent coins are now more sensibly
classified as having been struck on planchets that were punched out of
normal stock that was rolled too thick.
It shouldn’t have taken so long to demote these overweight coins.
Equally heavy cents and 5-cent coins occur in many other years. The
idea that the federal government would even contemplate such an
experiment in the middle of World War II is ludicrous. Copper was a
critical war material that needed to be conserved.
Also once suspected as being struck on an experimental planchet is
the illustrated 1915 Lincoln cent. It is slightly overweight at a
reported 3.2 grams and is composed of 75 percent copper and 25 percent
nickel (Coin World, June 10, 2002). It has since been
reclassified by most authorities (including uspatterns.com) as a
conventional off-metal error, possibly on a planchet for a Cuban
2-centavo piece, a coin the U.S. Mint was producing at the time. It
could also be an orphan off-metal error of unknown origin (mystery
planchets appear in many years).
While the Cuba 2-centavo coin officially weighs 3.5 grams, notable
variation in weight is seen among coins and planchets produced for
other countries during this general time period. For example, the
Argentina 10-centavo coin — whose copper-nickel planchets were
produced by the U.S. Mint from 1919 to 1920 — shows significant
variation (in my personal observation). It is also true that the Cuba
2-centavo coin measures 19.3 millimeters in diameter rather than the
19.05 millimeters that is standard for the U.S. cent. But the Cuban
blank would have been smaller before the strike, and even if it had
been wider than a cent blank and a cent collar, its passage through
the cent upsetting mill would have reduced its diameter to a size that
would fit into a cent collar.
The 1915 cent shows a poorly mixed alloy with streaks that are
especially noticeable on the reverse face. It’s unlikely that an
experimental planchet would be so sloppily fabricated. That
streakiness is very common on the previously mentioned Argentina
10-centavo planchets is perhaps telling.
Finally, there would seem to be no point to creating a
nickel-colored planchet, since the coin would be easily confused with
contemporary dimes and 5-cent coins at a time when copper was cheap
Our last example, a 1910 Lincoln cent, is currently encapsulated and
labeled as a uniface test strike. It is classified as JA1910-1/P3528
by uspatterns.com, although with some caveats. I think the caveats are
warranted and should be elevated to serious doubt. The coin’s weight
has never been reported and may be the same as a cent (its color is
certainly the same). While the planchet has been described as
“slightly larger than normal,” I don’t see any basis for this
conclusion. The coin was struck out-of-collar and the portion of the
coin lying beyond the die-struck obverse design shows obvious radial
striations all around. This would indicate that the planchet was
originally no wider than the die face and that the unstruck perimeter
squeezed out from beneath the die during the strike.
The available evidence indicates that this is probably a uniface
broadstrike. In other words, a cent planchet was struck on top of
another cent planchet while neither was confined by the collar.