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8547.10.40.00

Ceramic insulators to be used in the production of spark plugs for natural gas-fueled, stationary, internal combustion engines

Classification path

  1. 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
  2. Insulating fittings of ceramics
  3. Ceramic insulators to be used in the production of spark plugs for natural gas-fueled, stationary, internal combustion engines

Rates of duty

General (MFN)
3%
Column 2Cuba, North Korea, Russia, Belarus
60%
Unit of quantity
No.

Trade agreement rates

FreeGSP (lapsed since Dec 31, 2020), U.S.-Australia FTA, U.S.-Bahrain FTA, U.S.-Chile FTA, U.S.-Colombia TPA, AGOA (authorized through Dec 31, 2026), E, U.S.-Israel FTA, U.S.-Jordan FTA, U.S.-Korea FTA, U.S.-Morocco FTA, U.S.-Oman FTA, CAFTA-DR, U.S.-Panama TPA, U.S.-Peru TPA, USMCA, U.S.-Singapore FTA

Related lines in heading 8547

About heading 8547

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

Heading 8547 covers insulating fittings for electrical machines, appliances or equipment that are wholly of insulating material apart from minor metal assembly components, plus base metal electrical conduit tubing and joints lined with insulating material. It is split by material into ceramic, plastic and other insulating fittings, with separate lines for lined base metal conduit tubing and its joints.

Full guide to heading 8547

Products in this heading

  • Ceramic insulator bodies used in the production of spark plugs for natural gas-fueled stationary internal combustion engines
  • Other ceramic insulating fittings for electrical machines or equipment
  • Plastic insulating fittings such as plastic insulating bushings and sleeves
  • Other insulating fittings of materials other than ceramics or plastics
  • Base metal electrical conduit tubing lined with insulating material
  • Threaded joints for base metal electrical conduit tubing lined with insulating material
  • Other joints for base metal electrical conduit tubing lined with insulating material

Frequently asked questions

What is the HTS code for plastic insulating fittings?

Plastic insulating fittings are classified under 8547.20.00.00, with a general (MFN) rate of Free.

What is the duty on ceramic insulating fittings?

Other ceramic insulating fittings under 8547.10.80.00 have a general (MFN) rate of 3%. The ceramic insulator for production of spark plugs for natural gas-fueled stationary internal combustion engines under 8547.10.40.00 also has a general (MFN) rate of 3%.

How do I classify base metal electrical conduit tubing lined with insulating material?

Base metal electrical conduit tubing lined with insulating material is classified under 8547.90.00.20, with a general (MFN) rate of 4.6%. Threaded joints for that tubing go under 8547.90.00.30 at 4.6%, and other joints go under 8547.90.00.40 at 4.6%.

Source: USITC Harmonized Tariff Schedule, retrieved October 22, 2026.

HTS 8547.10.40.00: Ceramic insulators to be used in the production of spark pl..., 3% duty | HTSBase