(1965) Dime Pattern - RB-4030, INCO

Coin Details

Description

INCO experimental clad dime RB-4030, one of the later entries in the 1965 second-phase dime testing series. As the RB numbers climbed through the 4000 series, the alloy formulations typically represented increasingly refined variations designed to address specific performance shortcomings identified in earlier compositions. By mid-1965, the Denver and Philadelphia Mints were already tooling up for mass production of clad coinage, creating urgency in the testing program to finalize composition specifications. RB-4030 was struck at the Medallic Art Company on standard Roosevelt dime dies, using planchets prepared by INCO metallurgists to precise thickness and diameter specifications matching the production dime. The electromagnetic properties of each experimental alloy were of particular concern, as the nation's vending machine industry had invested heavily in mechanisms calibrated to detect silver's unique electrical conductivity. INCO's copper-nickel clad solution elegantly addressed this problem: the layered construction produced an overall conductivity profile remarkably similar to silver, even though neither the copper core nor the nickel-rich cladding individually matched silver's characteristics. This physics of composite materials became one of the key selling points for INCO's approach over competing proposals.

Rarity Notes

R-7 to R-8. Very few specimens documented. The 1965 INCO experimental dimes are among the most obscure entries in the modern pattern series.

Cross References

Research Blank RB-4030 (Gould/INCO experimental series)