Galvanized steel sheet is classified in the iron and steel chapter based on its base metal, not here. Heading 7905 applies only when the flat-rolled product itself is composed of zinc — not when zinc is merely a coating on another metal substrate.

The HS does not set a universal thickness cutoff between foil and sheet for zinc; the terms are used descriptively within the heading rather than as separate subheadings. Commercial invoices should specify thickness and width so that any applicable tariff-line distinctions at the 10-digit US level can be applied correctly.