Tariff monitor · Electrical & Wiring

Carbon Products and Insulators: Statutory & Effective Tariff Rates

Statutory HTS duty rates for 13 carbon products and insulators tariff lines (MFN Free–4.6%), from USITC. Effective rate May 2026: 15.25%; monthly history since 2014.

The short answer

  • The effective U.S. tariff on carbon products and insulators was 15.25% in May 2026, down from 20.46% a year earlier — calculated duties actually paid divided by customs value, from USITC data. The statutory MFN rate is Free–4.6% across 13 HTS lines in the 2026 schedule. China is the largest source, holding 22% of 2025 imports.

Statutory rates from the schedule

  • Carbon brushes and electrodes, electrical insulators, and insulating fittings — the wear and isolation parts inside motors and switchgear. This family covers HTS headings 8545, 8546, 8547: 13 eight-digit rate lines with MFN (column 1, general) rates of Free–4.6% in the 2026 schedule.
  • Chapter 99 flags on individual lines mark Section 301/232 overlay provisions (e.g. 9903.88.03) that apply on top of the MFN column.

What importers actually paid

  • Latest month on record (2026-05): 15.25% effective on $122.1M of imports, versus 20.46% in the same month a year earlier. The monthly archive holds 149 observations from 2014-01 through 2026-05.
  • In 2025, U.S. imports for consumption in this family totaled $1.3B in customs value and paid $224.1M in calculated duties: an effective tariff rate of 17.8%. The effective rate captures Section 301/232 overlays, exclusions, and special-program use that the statutory column cannot.
  • A year earlier the effective rate was 6.63%, so the duty burden rose 11.2 points.
  • Top source countries in 2025: China ($277.1M at 49.95%), Mexico ($167.7M at 3.2%), India ($144.3M at 15.35%), Japan ($119.0M at 8.65%), Germany ($91.2M at 7.38%).
  • For scale, 2025 imports in this family equal 0.7% of the U.S. nonmetallic mineral products industry's $176B gross output (2025, BEA).

Representative rate lines

  • 8545.11.00: Of a kind used for furnaces · MFN Free
  • 8545.19.20.00: Of a kind used for electrolytic purposes · MFN Free
  • 8545.19.40.00: Other · MFN Free
  • 8545.20.00.00: Brushes · MFN Free
  • 8545.90.20.00: Arc light carbons · MFN Free
  • 8545.90.40.00: Other · MFN Free
  • 8546.10.00.00: Of glass · MFN 2.9%
  • 8546.20.00: Of ceramics · MFN 3%

Frequently asked questions

  • What is the U.S. tariff rate on carbon products and insulators? Importers paid an effective rate of 15.25% in May 2026 (calculated duties ÷ customs value, USITC DataWeb). The statutory MFN rate is Free–4.6%; Section 301/232 overlays and special programs explain the difference.
  • What is the statutory MFN duty rate for carbon products and insulators? Free–4.6% across the family's 13 eight-digit HTS lines in the 2026 Harmonized Tariff Schedule (headings 8545, 8546, 8547).
  • Which countries supply the most carbon products and insulators to the U.S.? Top sources in 2025: China ($277.1M at 49.95%), Mexico ($167.7M at 3.2%), India ($144.3M at 15.35%). Sourcing is diversified: China holds 22% of imports.
  • How much carbon products and insulators does the U.S. import? $1.3B of customs value in 2025, paying $224.1M in calculated duties — an effective tariff of 17.8%.
  • Is the U.S. a net importer of carbon products and insulators? Yes — a net importer in 2025: $1.3B imported vs $595.2M exported (exports are 47% of imports).

About this data

  • Reference statistics derived from USITC published data. Not a customs ruling; verify rates with a licensed customs broker before relying on them.

Last reviewed 2026-05-12.