Analysis
HTS 2508.70.00 covers chamotte or dinas earth under heading 2508 (other clays (not including expanded clays of heading 6806), andalusite, kyanite and…).
Goods classified here enter the United States duty-free at the general (normal trade relations) rate, as do about 91% of the 78 tariff lines in chapter 25. Free here means free of the base duty only: origin-specific Chapter 99 duties such as Section 301 can still be owed.
Census statistics map these goods to NAICS 21232 (Sand, Gravel, Clay, and Ceramic and Refractory Minerals Mining and Quarrying), an industry of 2,617 US establishments employing 36,740 people. That is the industry code a US manufacturer of the same product would normally use.
All 5 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 |
|---|---|---|
| 2508.10.00 | Other clays (not including expanded clays of heading 6806), andalusite, kyanite and sillimanite, whether or not calcined; mullite; chamotte or dinas earths: bentonite | Free |
| 2508.30.00 | Other clays (not including expanded clays of heading 6806), andalusite, kyanite and sillimanite, whether or not calcined; mullite; chamotte or dinas earths: fire-clay | Free |
| 2508.40.01 | Other clays (not including expanded clays of heading 6806), andalusite, kyanite and sillimanite, whether or not calcined; mullite; chamotte or dinas earths: other clays | Free |
| 2508.50.00 | Andalusite, kyanite and sillimanite | Free |
| 2508.60.00 | Other clays (not including expanded clays of heading 6806), andalusite, kyanite and sillimanite, whether or not calcined; mullite; chamotte or dinas earths: mullite | Free |