(1964-65) Blank Pattern - RB-5320, INCO

Coin Details

Description

Experimental quarter-sized blank planchet RB-5320 from the INCO silver replacement evaluation program. The numbering gap between RB-5305 and RB-5320 indicates that several intermediate compositions (RB-5310, RB-5315) either were not produced or have not survived in collectible form. This gap is consistent with the pattern observed across the broader INCO experimental series, where some catalog numbers represent compositions that were tested but never progressed to the planchet-punching stage, having been eliminated based on preliminary metallurgical analysis of the rolled strip. RB-5320's survival indicates that this composition passed initial screening and was deemed worthy of full planchet preparation and evaluation. The physical characteristics of this blank — its weight, diameter, thickness, edge appearance, and surface color — would have been carefully measured and compared against the established specifications for a standard quarter-dollar planchet. Any significant deviation in these parameters could disqualify a composition regardless of its other merits, since the new coins needed to function in mechanical coin-handling equipment designed for the dimensions and weight of silver quarters.

Rarity Notes

R-7 to R-8. The numbering gaps in the series suggest limited production across the full catalog range, with some compositions surviving only as documentation entries.

Cross References

RB-5320 (Robinson-Breen catalog). INCO experimental blank planchet series, quarter-sized, 1964-65.