HTS 2521.00.00Limestone flux; limestone and other calcareous stone, of a kind used for the manufacture of lime or cement

What that translates to:Limestone and calcareous stone for lime or cement

Also written 25210000 or 2521.00.0000. Rates as CBP is collecting them today. Updated Oct 1, 2026.

Country of origin

Limestone and calcareous stone for lime or cement (HTS 2521.00.00) from China owe 37.5% in total duties as of Oct 1, 2026: no regular duty plus a 12.5% forced-labor tariff (Section 301) and a 25% China tariff (Section 301).

Total duty rate37.5%That's $3,750 on a $10,000 shipment.

Forced-labor tariffSection 301, since Jul 24, 202612.5%

China tariffSection 301, since May 10, 201925%

Regular dutyBase rate (MFN) in the tariff scheduleFree

Total duty37.5%

Court status: Challenged at the U.S. Court of International Trade in In re Section 301 Forced Labor Cases, Court No. 26-03555-3JP, before a three-judge panel. The plaintiffs, Learning Resources and others, have moved for judgment on the agency record, arguing that the action (91 FR 47318) exceeds USTR's statutory authority, is arbitrary and capricious, and is pretextual; 25 states, plaintiffs in Court No. 26-cv-03467-3JP, support them as amici (brief filed Sep 11, 2026). No ruling as of Oct 1, 2026, so the rate is unchanged.

Sources: USITC Harmonized Tariff Schedule, Revision 20 (2026); USTR, Notice of Actions in Section 301 Investigations (forced labor), 91 FR 47318, Jul 28, 2026; HTS 9903.05.31; USTR, Notice of Modification of Section 301 Action (List 3 raised to 25% from May 10, 2019), 84 FR 20459, May 9, 2019; HTS 9903.88.03.

Estimate your duty

Estimated duty—

Importing under HTS 2521.00.00? Talk to a licensed broker

Classification, filing, customs bonds and refund help. CBP publishes the brokers permitted at each port.

Find a licensed broker

Opens CBP's list of permitted customs brokers. We're not paid for this link.

Details for customs filings

Official description

Limestone flux; limestone and other calcareous stone, of a kind used for the manufacture of lime or cement

Legal text from the Harmonized Tariff Schedule, Revision 20 (2026), chapter 25: Salt; sulfur; earths and stone; plastering materials, lime and cement.

Statistical lines

The 10-digit numbers used on entry paperwork. They share this code's duty rates.

2521.00.0000 (2521000000)Limestone flux; limestone and other calcareous stone, of a kind used for the manufacture of lime or cement · reported in t

What changed for this code

Jul 24, 2026Forced-labor tariffs start on imports from 60 economies (Section 301)
Jul 22, 202625% Section 301 tariff on products of Brazil starts
Jan 1, 2026Section 301 tariff on Nicaragua starts at 0%, set to rise to 10% in 2027 and 15% in 2028

Questions about HTS 2521.00.00

What is the duty rate for HTS 2521.00.00?

The regular (column 1 general) rate printed in the tariff schedule is Free. Goods from China owe 37.5% in total as of Oct 1, 2026, including any additional tariffs. Additional tariffs depend on the country of origin; choose one above to see its full rate.

Is HTS 2521.00.00 subject to Section 301 tariffs?

Yes, for goods from 85 countries and territories as of Oct 1, 2026, including Algeria, Angola, Argentina, Australia, Austria. Choose a country above to see the rate and any exemptions.

Is HTS 2521.00.00 subject to Section 232 tariffs?

No Section 232 tariff applies to HTS 2521.00.00 as of Oct 1, 2026, from any country of origin.

HTSLookup shows the duties CBP collects on this code by country of origin. Antidumping or countervailing duties may also apply to some exporters; they're set per company and aren't shown.