(1964-65) Blank Pattern - RB-5410, INCO

Coin Details

Description

Experimental quarter-sized blank planchet RB-5410, the second documented entry in the RB-54xx composition group. The ten-unit spacing between RB-5400 and RB-5410 — wider than the typical five-unit intervals in the RB-53xx series — indicates that the RB-54xx blanks explored more broadly spaced compositions, testing distinct alloy concepts rather than the fine parametric variations that characterized the earlier series. This broader spacing is consistent with an exploratory phase of research, where the goal is to survey a wide range of possibilities rather than to optimize within a narrow band. The quarter-sized format of these blanks maintained consistency with the rest of the INCO program, ensuring that measurements taken on RB-5410 could be directly compared with results from any other quarter-sized blank in the catalog. The discipline of maintaining consistent dimensions across hundreds of experimental compositions was essential to the program's scientific validity — any variation in planchet geometry would have introduced confounding variables that could obscure the effects of the alloy changes being studied.

Rarity Notes

R-7 to R-8. Extremely limited production for evaluation purposes.

Cross References

RB-5410 (Robinson-Breen catalog). INCO experimental blank planchet series, quarter-sized, 1964-65.