Analysis
HTS 2605.00.00 covers cobalt ores and concentrates under heading 2605 (cobalt ores and concentrates).
Goods classified here enter the United States duty-free at the general (normal trade relations) rate, as do about 97% of the 39 tariff lines in chapter 26. Free here means free of the base duty only: origin-specific Chapter 99 duties such as Section 301 can still be owed.
It is the only US line under subheading 2605.00, 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 2605.00 points straight here.
Census statistics map these goods to NAICS 21229 (Other Metal Ore Mining), an industry of 58 US establishments employing 3,719 people. That is the industry code a US manufacturer of the same product would normally use.
The general rate of Free has not changed in any edition of the schedule since Jan 2023.