Analysis
HTS 2603.00.00 covers copper ores and concentrates under heading 2603 (copper ores and concentrates). US Customs collects import statistics for it under 5 ten-digit suffixes, reported in Cu kg.
The general rate is 1.7¢/kg on lead content, a specific or compound duty rather than a simple percentage, so the effective burden depends on the unit value of the goods: cheap goods pay proportionally more than expensive ones. Importers usually convert it to an ad valorem equivalent to compare it with other lines.
Goods that qualify under GSP, the Australia FTA, the Bahrain FTA, the Chile FTA, the Colombia TPA, and 12 others can enter duty-free instead of paying 1.7¢/kg on lead content. It is also eligible under GSP, the developing-country programme, which Congress has to renew; check whether GSP is in force on the entry date.
It is the only US line under subheading 2603.00, so the six-digit code used by every Harmonized System country and the eight-digit US line describe the same goods; a foreign tariff or an exporter's invoice showing 2603.00 points straight here.