Subtle design and relief modifications to the Jefferson 5-cent coin
would be required to extend die life while striking on planchets
composed of a harder alloy, according to conclusions reached in the U.S. Mint’s third
biennial report to Congress on alternative compositions for
According to the report, the changes would be made without
compromising the integrity of current designs, including sculptor
Felix Schlag’s original reverse.
“The coin striking process is a whole system, no part of which can
be changed without impacting another,” according to the report. “The
aspects include not only die shape and necessary pressure, but also
level of detail, sharpness of transitions, and relief height in the
coin’s design; overall curvature of the coins’ faces; and the
upsetting process, which preforms the blank’s material to the
Connect with Coin World:
up for our free eNewsletter
Like us on
us on Twitter
The third biennial report was publicly released July 12, seven
months after its submission to Congress as required under provisions
of The Coin Modernization, Oversight and Continuity Act of 2010,
Public Law 111-302.
Previous biennial reports were submitted to Congress in mid-December
2012 and 2014. The 2014 report concluded that, while a compositional
alternative exists for the Lincoln cent, the option does not offer
significant savings to bring production and related costs below face value.
The third biennial report’s research also reveals details about
other testing ongoing at the Mint, including on what is called
“pushback blanking.” Pushback blanking would change how blanks are
produced, with blanking equipment using two punches in opposition to
cut blanks from strip instead of the current Mint technique of using a
single punch to produce the blanks. Under this proposal, the Mint
would receive blanks manufactured by an outside vendor or vendors by
this method. In another production change, such blanks would be
punched from annealed strip, negating the need to anneal blanks after
they are punched out, before they are given an upset proto-rim.
Currently, the Mint receives coils of an alloy of 75 percent copper
and 25 percent nickel, from which it punches 5-cent coin blanks,
anneals them in a heating furnace to soften them, and then puts them
through an upset mill that forms the proto-rim on the planchet.
The report concludes, “While the Mint found pushback blanking to be
technically feasible, it could not verify savings; additional testing
will be conducted on a full size pilot die to establish high volume
production capability and refine the estimates for internal vs.
external annealing of the strip.”
The report adds: “Structured trials were completed with optimized
die designs and various rimming profiles on the 5-cent coin. The
results show promise and can yield incremental efficiencies in the
production of circulating coin and other Mint products.
“The Mint will continue validating these results and next steps
include small-scale coining trials to optimize 5-cent design and rim
profile followed by production-scale die life testing.”
The Mint’s research and development into coin alloy alternatives was
legislatively sparked by production costs for the Lincoln
copper-plated zinc cent and Jefferson copper-nickel 5-cent coin
reaching more than double the face value of the two denominations.
We examine an unusual example of ‘machine
Another column in the July 24 Coin World examines a VAM marriage
that deserves better.
Research for the third biennial report focused exclusively on the
Since the release of the second biennial report in 2014, production
costs for circulating coin denominations, which includes metal costs,
have dropped significantly.
2014 costs to produce the cent, 5-cent coin, dime and quarter dollar
were 1.66 cents, 8.09 cents, 3.91 cents and 8.95 cents, respectively,
while 2016 costs were recorded at 1.5 cents, 6.32 cents, 3.08 cents
and 7.63 cents, respectively.
Focus on 5-cent coin
Since 2014, the U.S. Mint has conducts testing on five different
alloy alternatives, one for the 5-cent, dime and quarter dollar and
the remaining four solely for the 5-cent coin:
➤ An 80/20 copper-nickel alloy composed of copper-nickel and
manganese for the 5-cent coin, with the material also tested for
cladding on the dime and quarter dollar, with the intent to adapt
results for the half dollar.
➤ C99750T-M — copper, nickel, manganese and zinc, tested for 5-cent
➤ C77000Y-O — copper, nickel and zinc, tested for 5-cent coin only.
➤ R52 Stainless Steel — Iron, nickel, chromium and carbon, tested
for 5-cent coin only.
➤ Nickel-plated CPZ — nickel plated on copper-plated zinc, tested
for 5-cent coin only.
Testing of the 80/20 alloy suggests the alloy is a seamless
alternative to the current composition for the 5-cent, dime and
quarter dollar denominations, with the same electromagnetic signature
for use in vending applications.
The C99750T-M option offers a potentially seamless alternative for
the 5-cent denomination, but additional testing is required for its
possible use as a replacement for the cladding layers on the dime and
quarter dollar, according to the third biennial report.
The C99750T-M alloy employs manganese and zinc to offset the higher
costs of nickel, while still maintaining the current electromagnetic signature.
The R52 stainless steel and the nickel-plated, copper-plated zinc
alternatives were studied as co-circulating options alongside the
denominations in their existing compositions.
The R52 stainless steel is an “austenitic steel.” According to
Britannica.com, “Austenitic steels, which contain 16 to 26 percent
chromium and up to 35 percent nickel, usually have the highest
corrosion resistance. They ... are nonmagnetic.”
While viable for coinage, the R52 stainless steel exhibited a
mottled, “orange-peel” effect around the rim caused from what is
called “strain hardening,” making the appearance less pleasing aesthetically.
If the R52 stainless steel option was adopted, according to the
third biennial report, “there would need to be a two- to three-year
transition period to develop internal practices to handle the higher
hardness of the material (similar to those for nickel-plated and
multi-ply-plated steels) and blank preparation/lubrication. This would
also coincide with a similar period for coin acceptors and handlers to
make the necessary changes to their installed base of coin acceptors
The nickel-plated, copper-plated zinc composition was not considered
a viable alternative for the 5-cent coin. “Although it exhibits a
different EMS than plated steels and is easier to coin, wear testing
of nickel-plated, copper-plated zinc indicated a failure because of
severe edge deformation, which led to a breakdown of the edge plating,
exposing the zinc core,” according to the report.
U.S. Mint officials indicate work is being pursued on the
development of two other co-circulating alternatives for
consideration. “One is a monolithic alternative for application to the
5-cent and the other is a plated construction suitable for application
to the 5-cent and 10-cent,” according to the third biennial report.