HTS 8547.10.40Insulating fittings for electrical machines, appliances or equipment, being fittings wholly of insulating material apart from any minor components of metal (for example, threaded sockets) incorporated during molding solely for the purposes of assembly, other than insulators of heading 8546; electrical conduit tubing and joints therefor, of base metal lined with insulating material:Insulating fittings of ceramics: Ceramic insulators to be used in the production of spark plugs for natural gas-fueled, stationary, internal combustion engines

What that translates to:Ceramic insulators for spark plugs of stationary natural gas engines

Also written 85471040 or 8547.10.4000. Rates as CBP is collecting them today. Updated Oct 1, 2026.

Country of origin

Ceramic insulators for spark plugs of stationary natural… (HTS 8547.10.40) from China owe 40.5% in total duties as of Oct 1, 2026: a 3% regular duty plus a 12.5% forced-labor tariff (Section 301) and a 25% China tariff (Section 301).

Total duty rate40.5%That's $4,050 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 schedule3%

Total duty40.5%

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.

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Official description

Insulating fittings for electrical machines, appliances or equipment, being fittings wholly of insulating material apart from any minor components of metal (for example, threaded sockets) incorporated during molding solely for the purposes of assembly, other than insulators of heading 8546; electrical conduit tubing and joints therefor, of base metal lined with insulating material: Insulating fittings of ceramics: Ceramic insulators to be used in the production of spark plugs for natural gas-fueled, stationary, internal combustion engines

Legal text from the Harmonized Tariff Schedule, Revision 20 (2026), chapter 85: Electrical machinery and equipment and parts thereof; sound recorders and reproducers, television image and sound recorders and reproducers, and parts and accessories of such articles.

Statistical lines

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

8547.10.4000 (8547104000)Ceramic insulators to be used in the production of spark plugs for natural gas-fueled, stationary, internal combustion engines · reported in No.

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 8547.10.40

What is the duty rate for HTS 8547.10.40?

The regular (column 1 general) rate printed in the tariff schedule is 3%. Goods from China owe 40.5% 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 8547.10.40 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 8547.10.40 subject to Section 232 tariffs?

No Section 232 tariff applies to HTS 8547.10.40 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.