(1964-65) Blank Pattern - RB-6020, INCO

Coin Details

Description

INCO experimental blank planchet RB-6020, representing a third composition in the RB-60xx subseries. This blank continues the exploration of alloy formulations within the RB-6xxx experimental framework, testing a composition that differs from both RB-6000 and RB-6010 in its metallic makeup. The consistency of ten-unit numbering intervals across the early RB-6xxx entries creates a structured experimental progression that would have facilitated systematic comparison of results. Each composition's properties were measured and documented using standardized test protocols, generating data that could be plotted against alloy composition to reveal trends and identify optimal formulation regions. The blank planchet's unadorned surface — devoid of the relief features that a struck coin would carry — made it the ideal substrate for surface analytical techniques such as X-ray fluorescence spectroscopy, which could determine the precise composition of the outer cladding layer without interference from die-imparted surface deformation. This kind of analysis was essential for verifying that the manufactured planchets matched the intended alloy specification.

Rarity Notes

R-7 to R-8. Very rare experimental blank from the less-documented RB-6xxx portion of INCO's program.

Cross References

RB-6020 (Robinson-Breen catalog). INCO experimental blank planchet series, RB-6xxx group, 1964-65.