Regular readers of this column may recall two previous articles
dedicated to stutter strikes (Dec. 28, 2009; July 25, 2011).
Arising under disparate conditions, stutter strikes are generated
by brief, early die contact and appear as an outlying crescent of
die-struck design that is restricted to one face. The continuation of
the hammer die’s downstroke generates the definitive strike, which
lies medial to the stutter strike.
Three types of stutter strikes have been defined. All are rare,
with Type III being the rarest. I had assumed that the hammer die
would generate the crescent of die-struck design in all three types.
That assumption has now turned out to be too restrictive, at least
with respect to Type III stutter strikes.
My assumption was falsified by an off-center dime that was
recently sent to me by Matt Dinger, owner of Lost Dutchman Rare Coins
in Indianapolis (www.ldrcoins.com). It displays a
Type III stutter strike on the reverse face, which was struck by the
anvil die. The outer edge of the struck tongue of metal also features
a chain strike. When struck, this planchet lay right next to a second
planchet. The two expanding edges collided with each other, producing
a common straight edge.
A Type III stutter strike depends on the presence of planchet or
coin that is bent, crumpled or that assumes some other complex
three-dimensional shape. The distortion can occur before, during, or
between strikes. The distorted disc proves unstable on a flat surface,
with a tendency to rock and slip when subjected to the touch of a die.
If a point of initial contact between the die and the distorted disc
lies near the edge of the die face, the affected area can slip
sideways and out of the striking chamber before the downstroke is completed.
I had always imagined that the highest point on the upper surface
of the unstable mass would be the area most likely to end up with
stutter strike. But on further consideration (prompted by this new
example) there’s no reason why a point of contact with the anvil die
couldn’t potentially receive a stutter strike as well. After all, the
base of the distorted disc would rest on the anvil die, supported at
two or more points. If one of those points happens to lie near the
edge of the anvil die, it could be pushed sideways and out of the
striking chamber in the course of the downstroke.
The dime planchet that received the off-center strike arrived in
the striking chamber with a long crack that presently shows
complementary beveled edges. Although the crack lies along the inner
margin of the definitive strike, it was clearly not caused by tensile
stresses generated during the strike. The obverse copper-nickel clad
layer has been smeared over the medial edge of the crack while the
reverse clad layer has been smeared over the lateral edge of the
crack. A tear caused by tensile stresses wouldn’t show any smearing of
the clad layers.
The crack and the smeared cladding could have been created
simultaneously by mechanical damage prior to the strike. However, I
think it’s more likely that the crack formed well before the strike,
while the smearing of the clad layers (and perhaps the bevel) occurred
during the strike. This scenario makes perfect sense if we assume that
the planchet was horizontally compressed after the crack developed.
This compressional damage caused the edges of the crack to telescope,
with the lateral edge riding over the medial edge. This overlap would
also have been key to the formation of the stutter strike.
Telescoping such as I’ve described is displayed in an off-center
1974 Mexico 20-centavo coin, illustrated this week. The facing edges
of a long fissure overlap in the unstruck crescent.
During the strike that produced the off-center dime, the die
margins more-or-less coincided with the telescoped edges of the crack.
When the hammer die made initial contact with the uplifted lateral
edge, the undershot medial edge simultaneously picked up partial
reverse lettering (ONE). As striking pressure increased, the medial
edge was forced out from beneath the overhanging lateral edge and
beyond the striking chamber. The smearing of the clad layers occurred
at this point. The lateral side of the crack remained within the
striking chamber; any design left on its upper surface by initial die
contact was wiped out by the completion of the hammer die’s
downstroke. The completion of the definitive strike left the two sides
of the crack aligned in the horizontal plane.
Additional supporting evidence for a single-strike scenario can be
found in the positioning of the outlying extra letters; these lie
opposite the slide zone of the obverse strike, rather than the obverse
design proper. There are also no signs of an earlier strike beneath
the definitive strike.
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