Forms such as ingots, cakes, slabs, and other cast shapes that are not electrodeposited cathodes, not tapered wire bars, and not cylindrical billets are typically classified here. The key is that the article must be refined copper in an unwrought state — it has not been mechanically worked — but its geometry does not match the specific definitions of the named subheadings in 7403.

A refinery certificate or assay report showing copper purity at or above the threshold for refined copper (typically 99.85% Cu or higher for electrolytic-grade material) is the standard supporting document. The production method — electrolytic refining or fire refining to high purity — should also be stated. CBP may request this documentation when the physical form alone does not make the distinction obvious.