1964 Quarter Pattern - RB-2230, INCO

Coin Details

Description

An INCO experimental quarter cataloged as RB-2230, struck on Washington Quarter dies as part of the comprehensive clad composition testing program of 1964. Medallic Art Company of New York, which served as INCO's contractor for producing these test strikes, was one of the most respected private minting firms in the United States, with extensive experience producing medals, tokens, and commemorative pieces. Their involvement ensured that the experimental quarters were struck to high standards of quality, allowing meaningful comparison with production-quality silver coins. The RB-2230 formulation falls in the middle of the RB-22xx sub-series and incorporates adjustments to layer bonding parameters identified through testing of earlier compositions in the sequence. The bond between the copper core and the nickel-alloy cladding was a particular focus of INCO's research: if the layers separated during striking, rolling, or normal circulation wear, the coin would become unusable. INCO developed proprietary diffusion bonding techniques that created a metallurgical transition zone between the layers rather than a sharp boundary, dramatically improving adhesion. This technology was so successful that clad coins produced using the adopted composition have shown virtually no delamination problems in over sixty years of circulation.

Rarity Notes

Extremely rare. Single-digit population estimated. These experimental compositions were produced in very limited quantities for evaluation purposes only.

Cross References

RB-2230 (Reed-Brenner), NGC ID: 61880