Analysis
HTS 4406.91.00 covers other: coniferous under heading 4406 (railway or tramway sleepers (cross-ties) of wood).
There is no general-rate duty on this line, which puts it with roughly 61% of the 257 tariff lines in chapter 44 that are also free. Free here means free of the base duty only: origin-specific Chapter 99 duties such as Section 301 can still be owed.
The other lines in the same group are 4406.11.00 (not impregnated: coniferous, duty-free), 4406.12.00 (not impregnated: nonconiferous, duty-free) and 4406.92.00 (other: nonconiferous, duty-free).
Census statistics map these goods to NAICS 321114 (Wood Preservation), an industry of 362 US establishments employing 11,819 people, the industry a domestic producer of these goods reports under.
All 3 neighbouring lines carry the same duty-free rate, so a borderline choice between them changes the statistics reported, not the duty paid.
Every edition we compared, from Jan 2023 to Oct 2026 (Rev. 22), shows the same general rate of Free.
Neighbouring lines
| Line | Description | General rate |
|---|---|---|
| 4406.11.00 | Not impregnated: coniferous | Free |
| 4406.12.00 | Not impregnated: nonconiferous | Free |
| 4406.92.00 | Other: nonconiferous | Free |