Analysis
HTS 7303.00.00 covers tubes, pipes and hollow profiles, of cast iron under heading 7303 (tubes, pipes and hollow profiles, of cast iron). US Customs collects import statistics for it under 3 ten-digit suffixes, reported in kilograms.
Goods from countries without normal trade relations pay the column 2 rate of 33% instead of nothing, so origin decides between free entry and a 33% duty.
Goods classified here enter the United States duty-free at the general (normal trade relations) rate, as do about 77% of the 250 tariff lines in chapter 73. Duty-free at the general rate does not rule out additional duties under Chapter 99, such as Section 301 or Section 232 measures, which depend on the country of origin.
It is the only US line under subheading 7303.00, 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 7303.00 points straight here.
Census statistics map these goods to NAICS 331511 (Iron Foundries), an industry of 269 US establishments employing 32,020 people. That is the industry code a US manufacturer of the same product would normally use.