HTS 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

All 7 HTS codes under heading 8547 (insulating fittings), with their duty rates from the 2026 HTS Revision 23. General duty Free to 4.6%.

Every line of heading 8547

  • 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.
  • 8547.10 Insulating fittings of ceramics.
  • 8547.10.40.00 Ceramic insulators to be used in the production of spark plugs for natural gas-fueled, stationary, internal combustion engines (No.): General 3%; Special Free (A,AU,BH,CL,CO,D,E,IL,JO,KR,MA,OM,P,PA,PE,S,SG); Column 2 60%.
  • 8547.10.80.00 Other (under: Insulating fittings of ceramics) (No.): General 3%; Special Free (A,AU,B,BH,CL,CO,D,E,IL,JO,KR,MA,OM,P,PA,PE,S,SG); Column 2 60%.
  • 8547.20.00.00 Insulating fittings of plastics (No.): General Free; Special none; Column 2 30%.
  • 8547.90.00 Other (under: 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): General 4.6%; Special Free (A,AU,B,BH,CL,CO,D,E,IL,JO,KR,MA,OM,P,PA,PE,S,SG); Column 2 45%.
  • 8547.90.00.10 Other insulating fittings (under: Other) (No.).
  • 8547.90.00.20 Conduit tubing (under: Electrical conduit tubing and joints therefor, of base metal lined with insulating material) (kg).
  • 8547.90.00.30 Threaded (under: Joints) (kg).
  • 8547.90.00.40 Other (under: Joints) (kg).

From MFG Calcs data: Carbon products and insulators

U.S. imports of carbon products and insulators (headings 8545, 8546, 8547) came to $1.26B in 2025, with $224M in calculated duty: an effective duty of 17.8%, every duty included.

Effective duty in Sep 2026: 16.0%, against 21.6% in Sep 2025.

Largest sources in 2025: China $277M at 50.0% effective duty; Mexico $168M at 3.2% effective duty; India $144M at 15.3% effective duty; Japan $119M at 8.7% effective duty; Germany $91.2M at 7.4% effective duty.

These are family totals from U.S. import statistics published through USITC DataWeb, not this heading's rate alone; effective duty is calculated duty as a share of customs value, an estimate, not a ruling.

About these rates

The rates are those printed in the 2026 HTS Revision 23, published by the U.S. International Trade Commission. A 10-digit statistical line takes the rates printed on the 8-digit line above it. Chapter 99 duties (Section 232, Section 301, IEEPA) depend on the product, the origin and the date, are charged on top, and are not included. A code here is a strong lead, not a ruling: confirm it with a customs broker or a CBP binding ruling.

Last reviewed 2026-11-12.