Dies are subject to brittle fracture, and this occasionally leads
to a piece of a die face breaking off. The general term for such
errors is “die break.”
The corner of the die (where die face meets die neck) is
particularly vulnerable to breakage. A die break that carries off the
rim gutter and at least a little bit of the adjacent field is called a
“cud.” Coin metal flows into the resulting void, leaving a lump on the
coin’s surface that is also called a cud.
Occasionally, a loose fragment that breaks off the corner of a die
does not fall away but is instead held in place. It is then termed a
“retained cud.” In the case of the anvil die, the die fragment is held
in place by the collar. In the case of the hammer die, the die
fragment is held in place by the bolts or clamp that secures the die
shaft. Retained cuds of the hammer die are quite rare.
Despite the frequency with which retained cuds occur,
misidentification is frequent both in and out of “slabs” (grading
In order to diagnose a retained cud, there must be clear evidence
of movement. The two key diagnostics to look for are vertical
displacement and horizontal offset.
Vertical displacement is more commonly encountered. A retained die
fragment will usually sink below the level of the intact portion of
the die face. This leaves a “step” on the surface of the coin at the
site of the break. The portion of the coin struck by the retained die
fragment is consequently elevated above the rest of the coin.
The illustrated 2010 Millard Fillmore dollar shows a retained cud
in which the letters e tru (of we trust) sit on a low plateau.
Vertical displacement is evident all around the break. It is one of
two examples struck by the same broken die sent to me by Fred
Weinberg. Remarkably, each example also lacks an edge inscription — a
completely unrelated error since the edge device is applied after the
coin is struck.
More severe vertical displacement is seen on a retained cud that
bisects the obverse face of a 2001-P Roosevelt dime illustrated here.
The left side of the break also shows the second diagnostic —
horizontal offset. Contiguous portions of the design are out of
register with each other, documenting sliding movement on the part of
the loose die fragment.
The reverse face of a 1985 Lincoln cent shows a large cud in the
southeast quadrant and an arcing, rim-to-rim die crack in the
northwest quadrant. Also called a “pre-cud” die crack, it shows
neither vertical displacement nor horizontal offset. It simply shows
lateral spread. The tenuously connected portion of the die splayed
outward, producing a wide crack into which coin metal flowed. This
left a jagged raised line on the coin. When the crack is even wider,
it is designated an asymmetrical split die.
Arcing rim-to-rim die cracks and asymmetrical split dies are often
mistaken for retained cuds.
When horizontal offset or vertical displacement is present and
involves the entire margin of the break, the long-standing assumption
has been that the die fragment was fully detached. But this conclusion
may not always be correct, especially when the signs of movement are
modest. Die steel is subject to bending, compression and distortion.
This can produce some degree of vertical displacement or horizontal
offset even when the die is still in one piece.
Vertical displacement within an intact die can be seen on the
illustrated 2007-P Roosevelt dime. It shows a long, curved bilevel die
crack on the face struck by the obverse (anvil) die. A later die stage
has the same crack connecting with the rim at 6:30 to form what we
would ordinarily diagnose as a retained cud. But is it really?
At least seven 2007-P Roosevelt dimes with presumed retained cuds
of the obverse (anvil) die are known. Are all of them fully detached?
I have my doubts.
Since we can’t directly observe the condition of the die that
strikes any coin with a presumed retained cud, we must admit to an
element of uncertainty in all but the most severe cases.
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