(1964-65) Quarter Pattern - RB-3220, INCO

Coin Details

Description

The final entry in the entire Reed-Brenner catalog of INCO experimental Washington Quarters, cataloged as RB-3220. This test piece represents the absolute conclusion of the International Nickel Company's landmark 1964-65 clad coinage composition research program — the last of over one hundred documented alloy formulations tested across the RB-1xxx, RB-2xxx, and RB-3xxx families. The significance of RB-3220 extends beyond its individual metallurgical properties: as the terminal composition in the program, it marks the point at which INCO's systematic investigation of copper-nickel clad alloys was deemed complete. Every relevant compositional question had been asked and answered, every promising alloy family had been explored to its boundaries, and the data accumulated across the full span of the program was sufficient to support a definitive recommendation to the United States Treasury Department. The composition that emerged from this program — 75% copper / 25% nickel cladding bonded to a pure copper core — has proven extraordinarily successful, remaining in continuous use for American dimes and quarters for over sixty years with no modification. RB-3220 is the final chapter of the research story that made this enduring composition possible, a fitting conclusion to one of the most comprehensive and consequential materials testing programs in industrial history.

Rarity Notes

Extremely rare. Population be 1-3 specimens. As the terminal entry in the entire Reed-Brenner catalog, RB-3220 holds unique significance among INCO experimental quarters.

Cross References

RB-3220 (Reed-Brenner), NGC ID: 61915