Of the current top three contenders for a change in composition for
the copper-nickel Jefferson 5-cent coin, two exhibit a yellowish hue
and the third is golden in color, according to a report to Congress
submitted Dec. 13 by the United States Mint.
One of those three alternatives — multi-ply-plated steel — is
produced by a process patented by the Royal Canadian Mint. Its use
would likely require the U.S. Mint pay a licensing fee.
The report also indicates that the top alternative composition for
the copper-plated zinc Lincoln cent — copper-plated steel — offers no
overall cost savings over copper-plated zinc.
The report to Congress was prepared by Concurrent Technologies
Corp., Johnstown, Pa., on behalf of the U.S. Mint. The 400-page report
represents the Mint’s first biennial report authorized under the Coin
Modernization, Oversight, and Continuity Act of 2010 (Public Law
11-302) concerning alternative metals for U.S. coins.
Although CTC presented conclusions and made recommendations based
on the research findings, U.S. Mint officials made no definitive
recommendations to Congress, arguing more research and validation of
results is necessary before any compositional changes can be recommended.
“More development, testing and evaluation must be completed prior
to finalizing a detailed specification for future coinage materials
that would include ‘appropriate changes to the metallic content of
circulating coins in such a form that the recommendations could be
enacted into law as appropriate’ [section 3(b) of Public Law
111-302],” according to the report.
CTC’s public outreach determined the general public would “readily
accept” a color change for the 5-cent denomination.
The research and development conducted jointly at the Philadelphia
Mint by the U.S. Mint and Concurrent Technologies Corp. was triggered
by overall costs of the cent and 5-cent coin registering more than
double face value. In addition, the 18-month study, concluded in
August 2012, also considered alternatives for the dime, quarter
dollar, half dollar and dollar coins.
The half dollar and dollar coins are still struck in circulation
quality, but only for sale at numismatic premiums above face value.
The quarter dollar is considered the work-horse of current
circulating coinage, and any change in composition would cause a major
disruption to vending companies and other concerns that use the coins
in automated transactions if equipment would need retrofitting because
of the change, according to the report.
The current copper-nickel clad composition for the quarter dollar
is also used for the dime and half dollar. The dollar coin is composed
of manganese-brass clad.
The report indicates it would take three to four years from the
selection of any alternative compositions for them to be introduced
CTC’s findings recommended that in the event of changes in the
composition of more than one denomination, that they be introduced
into circulation on or about the same date to ensure a seamless transition.
The U.S. Mint’s research and development concentrated on testing
of coinage strip, raw blanks and planchets (finished blanks with an
upset, or raised rim, ready for striking) that were supplied by
current and potential vendors.
The three current suppliers to the U.S. Mint provided samples for
testing: Jarden Zinc Products, Greeneville, Tenn., finished cent
planchets; and the two suppliers of coinage strip for punching blanks
for the 5 cent through dollar denominations, Olin Brass Products in
East Alton, Ill., and PMX Industries in Cedar Rapids, Iowa, also
provided samples for testing.
In addition to those three firms, potential suppliers who
contributed to the U.S. Mint’s Research and Development efforts included:
➤ Royal Canadian Mint, Winnipeg, Manitoba.
➤ Royal Mint, Great Britain.
➤ Carpenter Technology, Wyomissing, Pa.
➤ CVMR Corp., Toronto.
➤ Vale Inco Ltd., Toronto.
➤ Ryerson Inc., Chicago.
According to the United States Mint, upon starting research, it
reduced the potential alternative metals options to 32 available
industrial metals selected from the periodic table of 80 metallic
Of the 32 metals tested, three — aluminum, zinc and
iron (steel) —were considered as potential long-term alternative
metals, in addition to copper and nickel, which are the primary metals
used in current U.S. coinage.
From the three, plus the two incumbent metals, nine alloy groups,
comprising 29 potential alloy combinations, were identified for
consideration and testing.
➤ Aluminum — A commercially available grade 5052 was identified by
CTC for test and evaluation. The CTC report recommends against the use
of aluminum or aluminum alloys.
➤ Aluminized steel — Composition is available as steel sheet
coated with aluminum. As the sheet is surface coated, coins made of
the composition would have an unprotected exposed edge after blanking.
The exposed edge would rust.
➤ Copper-plated zinc — The current Lincoln cent composition. If
used for denominations other than the 1-cent coin, its different EMS
would result in increased conversion costs and its color (brownish)
would create some short-term confusion.
➤ Multi-ply plated steel — Multi-Ply-plated steel is made by a
patented process developed by the RCM in which a flash nickel layer is
plated onto low-carbon steel, followed by a (noncyanide) plated copper
layer and a second nickel layer. Used as circulating coin material in
Canada and other countries.
➤ Copper-plated steel — This composition is a plated product
utilized interchangeably with copper-plated zinc by the RCM. In
considering this option for the United States, cost estimates did not
demonstrate a cost savings, since a heavier copper plating would be
required than used on the current copper-plated zinc cent.
➤ Copper-plated steel sheet — This is steel sheet plated with
copper. Cost modeled, but not tested.
➤ Nickel-plated steel — This is a nickel-plated steel alternative
developed by the Royal Mint, with the name aRMour. It is composed of
nickel plated on a low carbon steel. Coating is much thicker than the
RCM multi-ply composition.
➤ Stainless steel — Two distinct grades of stainless steel were
considered, one magnetic and one nonmagnetic.
➤ Tin- and copper-plated zinc — The proprietary name of this
composition is Dura-White. Dura-White is the name of a patent-pending
process developed by Jarden Zinc Products. A zinc planchet is first
plated with copper and then with tin. The tin coating provides a color
similar to the current coin compositions.
➤ Leaner copper-based alloys — Modified copper-based alloys leaner
than the current coin composition of 75 percent copper and 25 percent
nickel (used for the 5-cent coin, and the outer layers of dime,
quarter dollar and half dollar). The alloys were identified as 669z
(PMX); G6 Mod (Olin Brass Products); and 31157 (Jarden Zinc Products).
Using the metals prices defined on the London Metal Exchange,
Concurrent Technologies Corp. identified iron (and steels), zinc and
aluminum alloys as the leading alternative candidates that could
potentially reduce the cost of coinage by replacing copper and nickel
to varying degrees.
Under the joint CTC-U.S. Mint research conducted under U.S. Mint
oversight, two rounds of progressive trial strikes were executed at
multiple striking pressures on the coinage presses, according to the
report. Twenty-five unique material-denomination combinations were
tested among the two striking trials.
Also, four materials were
corrosion tested only for alternative compositions for the
Presidential and Native American dollars, both of which are struck in
circulation quality only for numismatic products intended for collectors.
Nonsense dies used
All of the experimental trial strikes were produced with obverse
nonsense dies depicting different portraits of Martha Washington for
the cent, 5-cent and quarter dollar test pieces, each with scrambled
lettering. The reverse designs on the test pieces, also with scrambled
letters, were intended to replicate the detailed images common to
current circulating coins.
The reverse cent nonsense die design resembles the Lincoln, Shield
cent reverse. The reverse design for the 5-cent test pieces features a
different rendition of Monticello than that which appears on the
current Jefferson 5-cent coin.
The quarter dollar nonsense die reverse incorporates elements of
the current America the Beautiful quarters.
Test pieces produced from these striking trials were struck to
test potential alternative material candidates for the cent, 5-cent
coin, dime, quarter dollar and half dollar.
Consistent with current U.S. coinage, the project team assumed
that the dime, quarter dollar and half dollar coins would continue to
be constructed of like materials in the same relative weight
proportions as their assigned monetary value. Of these three
denominations, only quarter dollar nonsense pieces were struck,
according to the report.
Nonsense pieces struck during the two trial strike periods were
submitted by the U.S. Mint to three coin-acceptance equipment
manufacturers to determine which of the material/denomination
combinations could be introduced into circulation without significant
modifications to existing coin-processing equipment.
coin acceptance equipment manufacturers to which nonsense cents,
5-cent coins and quarter dollars were distributed are Coinco,
headquartered in St. Louis; MEI, headquartered in Malvern, Pa.; and
SCANCOIN, headquartered in Malmo, Sweden.
Richard A. Peterson, deputy director of the U.S. Mint, said all of
the struck nonsense pieces sent to Coinco, MEI and SCANCOIN were
subsequently retrieved after field testing so none could end up in the
hands of collectors. As the U.S. Mint continues its research and
development and expands its alloy candidates and the dissemination of
struck nonsense pieces for additional testing by more potential end
users, the Mint plans to keep track of the location of each of the
nonsense pieces distributed so none wind up in numismatic channels,
The CTC-prepared report recommended, “Each of these nonsense
pieces need to be well controlled since such nonsense pieces would be
highly prized by numismatists.”
The report presents the following findings, conclusions and
recommendations, based on the research and development conducted thus far:
➤ Maintaining the existing coin dimensions, i.e., diameter,
thickness, for all future coin regardless of the composition, since
conversion costs to coin-processing equipment if dimensions were
changed would be cost prohibitive.
➤ Ferromagnetic materials should not be considered for circulating
U.S. coins, except potentially for the cent.
➤ Maintaining the current copper-plated zinc composition for the
Lincoln cent, even though current production costs total more than
double face value. The current composition for ready-to-strike
planchets supplied by Jarden Zinc Products is a 99.2 percent zinc, 0.8
percent copper planchet plated with pure copper. The top alternative
composition — copper-plated steel planchets from the Royal Mint —
offer no cost savings, according to CTC. Other potentially low cost
alloys failed to meet one or more of the other provisions of the 2010
legislation, according to CTC. “Aluminum alloys jam or destroy some
types of coin-acceptance or coin-handling equipment, which would
require costly upgrades to enable this equipment to process
aluminum-based coins,” according to CTC’s findings. “The
surface-modifying technologies (to reduce tarnish and/or corrosion of
single-alloy coins) evaluated in this study lacked application
maturity. Other alternatives did not offer sufficient corrosion and/or
➤ Continue development of copper-based alloys for the 5-cent
denomination, two of which result in a yellow hue and a third a
slightly golden appearance. All three alternatives would weigh less
than the current 5 grams for the Jefferson 5-cent coin composed of a
homogenous alloy of 75 percent copper and 25 percent nickel, and
therefore would require retrofitting of vending and other
coin-acceptance equipment to accommodate the lighter weight. The
reduction in weight is based on the diameter remaining at the current
21.21 millimeters, but the thickness likely changing. Savings by using
one of the top alternatives would be generated through decreased
annealing and ancillary energy costs, not metal costs.
➤ For the dime, quarter dollar and half dollar, consider replacing
the current clad composition of two outer layers of 75 percent copper
and 25 percent nickel bonded to a core of pure copper with a
copper-based alloy, 669z, clad to C110 copper alloy.
“Based upon validation testing completed in this study, quarter
dollar nonsense test pieces of this construction showed evidence of
being a seamless alternative to the incumbent quarter dollar coin,”
according to CTC. CTC’s recommended alternative would also cast a
yellow hue, which could cause some confusion with the dollar coins.
CTC recommended that the current composition for the dollar coins,
manganese brass clad — outer layers of 77 percent copper, 12 percent
zinc, 7 percent manganese and 4 percent nickel bonded to a core of
pure copper — be maintained. The research and development testing only
examined alloy alternatives for the dollar coin based on steam
corrosion tests. None of the four alternatives steam-tested offer any
Should any changes in circulating coin compositions be made, all
denominations whose composition is changed should be introduced
approximately at the same time to minimize conversion costs to
The report also recommended the Mint continue long-range research
on surface engineering of zinc or low-carbon steel for the cent, which
may uncover a useful technology that would permit the elimination of
the copper plating and its associated costs. CTC offered as
suggestions inexpensive paints or colored particles on bare zinc
covered with a wear-resistant coating
For lower denomination coins, CTC recommends continued pursuit of
stainless steels; for higher denomination coins, the report recommends
continued study of stainless steel alloys clad to C110 copper alloy
for the dime, quarter dollar and half dollar, with the electromagnetic
signatures to replicate the current compositions (which would negate
the need to upgrade coin-processing equipment for the dime and quarter).
Plated alloys for denominations higher than the quarter dollar
were not recommended by CTC because they pose security and fraud
issues. “Plated-steel coins require substantially broader acceptance
limits in automated coin-processing equipment, with significant
impacts to coin sorting and counting, and would lead to less secure
coin identification standards,” according to CTC.
It was recommended the Mint maintain its current suppliers for
materials used to produce circulating coins.
Use of steel, stainless steel and/or aluminum would likely require
expanding the pool of alternative metals suppliers.
The December report suggests that validation testing must be
completed for proposed changes to the materials of construction for
circulating coins to quantify:
➤ The variability of material properties from multiple lots of
proposed coin materials; and
➤ The variability in finished coins through completion of
simulated coin production runs each of at least 1 million test pieces.
“Coins of any given denomination should be made at different times
and under a variety of common production conditions,” according to the
report. “Samples of coins from each of these test conditions should
then be tested to establish more robust standard deviations in the
characteristics to be expected from volume production of these coins.
“These tests must also assess the impact of temperature and
humidity; coin scratches, gouges, tarnish, corrosion, wear and slight
bends; and other stakeholder-defined test conditions.”
Complicating the management of coin production, according to the
report, orders from the Cash Product Office of the Federal Reserve are
estimated one month in advance, but the actual quantity of coins
ordered can still vary by as much as 30 percent.
“The actual number of coins required is not defined by the Federal
Reserve Banks until the finalization of the order as production
actually begins,” according to the report. “These shifting, short-term
changes in coin demand impact the required installed machine capacity
in addition to having an effect on staffing and the supply chain.”
The 400-page report can be found online at www.usmint.gov/about_the_mint/PDFs/Current_Technologies_Corporation_Report_Alternative_Metals_Study_August_31_2012.pdf. ■