(1964-65) Blank Pattern - RB-5400, INCO

Coin Details

Description

The opening entry of the RB-5400 subseries within INCO's experimental blank planchet program, RB-5400 marks a new group of quarter-sized blank compositions. The transition from the RB-53xx to the RB-54xx numbering block signals a shift to a different family of experimental alloys, potentially exploring compositions with fundamentally different layer architectures, alternative cladding thicknesses, or novel alloying elements not present in the RB-53xx formulations. This numbering convention allowed INCO and Treasury evaluators to organize the extensive experimental output into logical groups that could be compared both internally (within a series) and externally (between series). The RB-5400 blanks may represent compositions that responded to feedback from the earlier testing — emphasizing properties where the RB-53xx alloys fell short, or pursuing a different balance of the competing requirements for electromagnetic compatibility, visual appearance, manufacturing feasibility, and cost. The blank planchet format continues to serve as the purest expression of each alloy's intrinsic character, unmediated by the complexities of the die-striking process.

Rarity Notes

R-7 to R-8. Very rare experimental planchet opening a new composition group in the INCO blank series.

Cross References

RB-5400 (Robinson-Breen catalog). INCO experimental blank planchet series, quarter-sized, 1964-65. Opens the RB-5400 composition group.