(1964-65) Blank Pattern - RB-5325, INCO

Coin Details

Description

INCO experimental quarter-sized blank RB-5325, continuing the systematic exploration of alloy compositions for the silver replacement program. Each blank in the RB-53xx series documents a distinct metallurgical formulation, and RB-5325 represents one of the more closely spaced composition variants — separated from RB-5320 by only a single increment — suggesting that INCO's engineers were fine-tuning a promising alloy composition in this portion of the experimental matrix. Fine adjustments of even a fraction of a percent in nickel or copper content could meaningfully affect an alloy's electromagnetic signature, and the quest for an exact electromagnetic match to 90% silver drove much of the fine-grained compositional variation visible in the RB catalog. The International Nickel Company brought to this challenge not only metallurgical expertise but also extensive experience with electromagnetic coin acceptance testing, having worked with vending machine manufacturers worldwide to develop alloys for foreign coinage transitions. This background informed INCO's ability to predict which compositions would satisfy the electromagnetic requirements before physical testing confirmed the prediction.

Rarity Notes

R-7 to R-8. Extremely rare experimental planchet produced in minimal quantities for Treasury evaluation.

Cross References

RB-5325 (Robinson-Breen catalog). INCO experimental blank planchet series, quarter-sized, 1964-65.