The blanking operation involves a long strip of coin metal passing
beneath a battery of blanking dies (punches) and above a perforated
base plate. Each blanking die forces a disc of metal through the hole underneath.
In order for a coin blank to be punched out cleanly, the blanking
die and the hole in perforated base plate must have smooth, sharp
edges. If the edge of either element gets dull or chipped, this could
prevent a blank from detaching from the coin metal strip. At the very
least, it can leave an irregularity — a burr — poking up from the
newly punched blank. That burr will then be folded over during the
upsetting operation and, ultimately, struck into the coin. At this
point the error is known as a “rolling fold.”
Identified, described and named in the 1990s by error researcher
Arnold Margolis, rolling folds are distinct from other types of burrs
that affect blanks and planchets. As seen in the illustrated 1972-D
Jefferson 5-cent coin, a rolling fold is a low, broad, symmetrical
tongue of metal that intrudes a short distance into the field. Few are
larger than this one.
Some rolling folds are too small to even reach the field and are
thus restricted to the design rim. As is true of any struck-in piece
of metal, this rolling fold is flush with the field and surrounded by
No disturbance is ever seen on the portion of the edge adjacent to
a rolling fold. This is in marked contrast to burrs that form later in
the minting process. Called “rim burrs,” these can theoretically be
generated by the upsetting mill, the feeder finger, or any other
moving part encountered prior to striking. Judging from groups of
coins I’ve examined with identical-looking rim burrs in identical
locations on the face struck by the hammer die, a significant
percentage of such errors must be generated by the feeder finger
immediately before the strike.
The illustrated 1972 Kennedy half dollar shows a classic rim burr
invading the last two digits of the date. It takes the form of a long,
narrow spur with a sharp tip. The edge of the coin is gouged and the
design rim is damaged, exposing the copper core.
A second rolling fold is seen on the obverse face of a 1967
Washington quarter dollar. The copper-nickel clad composition of this
coin provides additional diagnostics. The reeding is intact and the
edge undisturbed. The copper core does not extend onto the rolling
fold, a characteristic common to all clad coins with rolling folds. In
contrast, rim burrs often carry along a significant amount of copper
The rolling fold in this example lies on the face derived from the
original upper face of the coin metal strip. We can tell this is the
case because the reverse clad layer has been dragged onto the edge a
little bit, obscuring some of the copper core. This effect occurs on
all clad coins and occurs when the blank is forced through the hole in
the perforated base plate.
The presence of the rolling fold on the upper face is consistent
with a blanking die that was dull or that had a small chip on its
edge. Theoretically, rolling folds should be largely or exclusively
restricted to the face originally impacted by the blanking die, since
it is only here that a vertically oriented burr can form.
Rolling folds are quite rare, but you wouldn’t know it judging
from eBay listings. Many errors on that auction site are identified as
rolling folds but are something else entirely. Some are rim burrs.
Some represent other forms of pre-strike damage, as seen on this 1966
Washington quarter dollar. On this example a wide flap was torn up and
folded over, but it occurred after blanking. Some purported rolling
folds are lamination errors while others are retained cuds. And some
represent post-strike damage.
Collectors in search of a bona fide rolling fold must carry in
their heads the handful of critical diagnostics described here.
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