Analysis
Subheading 7307.21 covers flanges, within heading 7307. The first six digits are shared by every country that uses the Harmonized System, so this part of the code is the same in the US, UK and EU schedules; the 2 US tariff lines below it are national.
None of its 2 lines is duty-free at the general rate. Rates run from 3.3% to 5.6% with a median of 4.449999999999999%, so the line you choose sets the duty.
The US splits it as follows: 7307.21.10 for not machined, not tooled and not otherwise processed after forging (3.3%) and 7307.21.50 for flanges: other (5.6%).
By Census's concordance, most of its statistical lines are made by Other Metal Valve and Pipe Fitting Manufacturing (332919). Those are the NAICS industries a US producer of these goods would report under.
Goods only reach 7307.21 once they fall within heading 7307 (tube or pipe fittings (for example, couplings, elbows, sleeves), of iron or steel). Under General Rule 6, subheadings are then compared only with others at the same level, so a product is matched against its siblings, not against lines elsewhere in the chapter.
Tariff lines
| Line | Description | General rate |
|---|---|---|
| 7307.21.10 | Not machined, not tooled and not otherwise processed after forging | 3.3% |
| 7307.21.50 | Flanges: other | 5.6% |