The thickness threshold is 0.15 mm measured excluding any backing. Strip or sheet thicker than 0.15 mm falls under 7409; material at or below 0.15 mm — whether backed or unbacked — is copper foil under 7410. Accurate thickness measurement at the time of entry is essential for correct classification.

No. Brass (copper-zinc alloy) plates and strip have their own subheadings (740921 in coils, 740929 not in coils), while bronze plates and strip are separately classified under 740931 and 740939. The alloy composition determines which subheading applies.