1964 Half Dollar Pattern - RB-2705, INCO

Coin Details

Description

INCO experimental clad half dollar pattern RB-2705, struck from Kennedy half dollar dies on a variant alloy composition from the RB-2700 baseline. This piece explores a different metallic formulation for the half dollar denomination, with changes to the proportions of nickel, copper, or other elements in either the cladding layers or the core material. The half dollar presented a distinctive set of engineering challenges compared to the dime: its larger diameter and greater thickness meant that the clad bonding between outer layers and core needed to withstand significantly greater striking forces, and the exposed edge of the clad sandwich was more prominently visible, making any unsightly color contrast between core and cladding layers more noticeable to the public. INCO's metallurgists paid particular attention to edge appearance in the half dollar compositions, as the visible copper-colored stripe on the edge of clad coins would become one of the most immediately recognizable features of the post-1964 coinage — and potentially one of the most controversial, since it made the absence of silver instantly obvious. The evaluation of RB-2705 alongside other compositions in the series helped Treasury officials understand the range of visual and functional trade-offs available for the half dollar denomination.

Rarity Notes

R-7 to R-8. Extremely rare, with only a few specimens produced for each alloy variant in the half dollar series.

Cross References

RB-2705 (Robinson-Breen catalog). INCO/Medallic Art Company experimental clad coinage program, 1964.