(1965) Quarter Pattern - RB-4105, INCO

Coin Details

Description

INCO experimental clad quarter RB-4105, the second composition variant in the 1965 quarter testing series. This piece differs from RB-4100 in its specific alloy ratios, adjusting the nickel percentage in the outer cladding layers or modifying the copper core composition. The quarter denomination received the most extensive testing of any denomination in the INCO program — the 1964 first phase alone generated over 80 distinct quarter compositions across the RB-1000, RB-2200, RB-2300, and RB-2500 sub-series — reflecting the quarter's commercial importance as the workhorse coin of American commerce. Vending machines, parking meters, toll booths, and laundromats all depended heavily on the quarter, making its successful transition to clad composition a matter of significant economic consequence. RB-4105 was struck at the Medallic Art Company on standard Washington quarter dies, producing a coin that bears John Flanagan's familiar George Washington portrait on the obverse and the heraldic eagle reverse, identical in appearance to a production quarter except for its experimental composition. The physical weight and dimensions were calibrated to match the production specification as closely as possible, ensuring that test results would translate directly to mass production.

Rarity Notes

R-7 to R-8. Very few specimens known. The 1965 quarter experiments are scarcer than the more extensively produced 1964 series.

Cross References

Research Blank RB-4105 (Gould/INCO experimental series)