A bar or rod of copper-zinc alloy (brass) is classified under 740721 regardless of the copper content percentage, because the heading explicitly separates brass as a named alloy group. Refined copper bars with minimal alloying go under 740710.

Bars and rods have uniform solid cross-sections (circular, rectangular, hexagonal, etc.) throughout their length. Profiles have cross-sections that do not conform to those standard shapes — for example, T-sections, angle sections, or custom extruded shapes. Both are covered within 7407, but the distinction can matter at the 10-digit US tariff line level.