The information below is primarily excerpted from Pollock and from the August 30, 1993 and September 6, 1993 issues of Coin World by Kenn Henderson.
This metallurgical trial was produced by Dupont in 1964. They were one of several companies the U.S. Mint commissioned to find a suitable alloy replacement for silver.
The obverse is of Benjamin Franklin and the Reverse contains the Dupont emblem with the inscription "This token made from explosion bonded 'Detaclad'".
Detaclad is a patented process for laminating 75% copper, 25% nickel to a copper core.
Examples are known as follows:
75% copper, 25% nickel on a copper core (detaclad) P5391 with 520 examples believed to have been struck.
96% copper, 4% nickel on a copper core (detaclad) P5393. Two were offered in Heritage's January 2006 sale of the Jules Reiver collection.
Photo courtesy of Heritage.