The consignor of items documenting Revere Copper & Brass Inc.’s
1964 experiments that led to copper-nickel clad U.S. coinage is
hopeful that the records her father kept will go to someone who will
appreciate the history of that testing.
That historical material,
including an experimental token
and three square planchets, all made of the then-new copper-nickel
clad composition, is heading to auction.
The Michigan woman, who has requested anonymity, is the daughter
of Richard M. Brown, who was the methods and metallurgical manager at
Revere Copper and Brass Inc. in Detroit in 1964. That firm was
“responsible for the hot rolling process of the U.S. Mint’s coinage
metal, which was using DuPont’s explosive bonding process,” the woman
told Coin World May 30.
The experimental token was struck in 1964 on planchets punched
from strip produced through a method of explosion welding patented as
Detaclad by manufacturer DuPont, which partnered with Revere. The
copper-nickel clad composition was produced as a substitute for the
silver alloy used for U.S. coinage.
The token and planchets are only part of the consignment. They are
accompanied by documentation detailing the joint Revere-DuPont
experiments: an apparently unique photographic album compiled by Brown
illustrating the rolling process, along with a copy of an article
about the testing.
Richard Brown produced the bound volume titled “A Pictorial
Summary of the Conversion of Cupro-Nickel Coinage Metal for U.S. Mint”
— which is part of the consignment — containing 21 color photographs
documenting the Detaclad process.
According to the consignor, the photographs and documentation are
the last remaining record of Revere’s experimentation, adding to their
All of the materials are offered as a single lot in Heritage
Auctions’ June 5 to 9 sale held in conjunction with the Long Beach
Coin, Stamp & Sports Collectible Expo in Long Beach, Calif.
A presentation token
The Detaclad token in the auction features a portrait of Benjamin
Franklin on the obverse facing left with his name above, the date 1706
on the left and 1790 on the right. In very small print at the bottom
near the rim is AUG C. FRANK CO. (August C. Frank Co., the
Philadelphia firm that actually struck the pieces).
The reverse of the token has the DuPont logo encircled in the
center and THIS TOKEN MADE FROM EXPLOSION BONDED “DETACLAD” TM
circling close to the rim.
The token in the auction is the diameter of a quarter dollar and
has a plain edge.
Heritage grades the token, which is not in a third-party grading
service holder, as Mint State 62.
According to Kenn Henderson, who wrote about the Detaclad
experiments in the Sept. 6, 1993, issue of Coin World, Detaclad “is a
patented process for laminating 75/25 copper-nickel to the copper core.”
Henderson notes, “A special set of dies were made to produce 500
pieces for presentation” featuring the Franklin portrait. The DuPont
token in the sale would be from that mintage of 500 pieces.
A chance meeting
According to Jim Stoutjesdyk of Heritage: “I met a lady ... at the
Michigan State Numismatic Society coin show in April. She came up to
my bourse table and began telling me about her father, Richard M.
Brown. ... She explained that Revere had the government contract to
roll the coinage metal for the new clad coinage that was being produced.
“Her father was involved with the testing and development of the
new ‘sandwich coins’ (as she referred to them) from the earliest
stages. This included helping to determine the electromagnetic
properties needed to trip the mechanisms in the existing coins boxes
in vending machines and pay telephones the same way that silver coins
were already doing. She explained that her father photographed and
described every step of the process used to create the new clad
coinage metal and then [she] showed me the folder that he assembled. I
was really amazed to see this pictorial history ... that provided a
fascinating insight into this important transitional period of modern
U.S. coinage history.”
The consignor told Coin World that her father spent time at the
Denver Mint in 1964 in working with Mint officials and others to
ensure that the electromagnetic properties of the new composition were
compatible with existing coin-operated equipment, especially
telephones. Operators of coin-operated equipment were insistent that
any new coinage be usable in existing machines without the need for
She also noted that he spent time “behind bunkers” at the
government testing grounds at Los Alamos, N.M., where the explosive
welding process was tested. Los Alamos was also the site where the
first atomic bombs were developed.
She also recounts that she took the square planchets to school for
show-and-tell in 1964, relating to her classmates that their coins
would soon look like the planchets.
Of the three square planchets, one measures 19 millimeters by 19
millimeters and is “thin”; one measures 20 millimeters by 20
millimeters and is just slightly thicker; and the third measures 21
millimeters by 21 millimeters and is 6 millimeters thick.
The EXPLOSION BONDED inscription on the reverse of the token
refers to the method used in producing coinage strip composed of two
outer layers of copper-nickel and an inner core of pure copper.
According to the Wikipedia article on the topic, chemical
explosives were used in welding the separate layers of metal to each
other. “The process does not melt either metal, instead it plasticizes
the surfaces of both metals, causing them to come into intimate
contact sufficient to create a weld,” according to the Wikipedia
article. “Large areas can be bonded extremely quickly and the weld
itself is very clean, due to the fact that the surface material of
both metals is violently expelled during the reaction.”
DuPont patented the Detaclad process on June 23, 1964.
Contact Heritage at its website, www.ha.com. ■