What is the U.S. tariff rate on carbon products and insulators?

USITC calculated duties imply an effective rate of 14.46% in Jun 2026 (calculated duties ÷ covered customs value, USITC DataWeb). The parseable Column 1 General line-rate range is 0%–4.6%; individual lines are called “Free” only when the official General field is literally Free, and product, origin, preference and tariff mix can contribute to the observed-rate difference.

What are the statutory MFN line rates for carbon products and insulators?

The parseable Column 1 General line-rate range is 0%–4.6% across the family's 13 eight-digit HTS lines in the 2026 Harmonized Tariff Schedule (headings 8545, 8546, 8547). “Free” means the official General field is literally Free for a line; it does not determine final entry liability.

Which countries supply the most carbon products and insulators to the U.S.?

Top retained sources in 2025: China ($277.1M at 49.95%), Mexico ($167.7M at 3.2%), India ($144.3M at 15.35%). China holds 22% of total family import customs value. Retained sources cover 83.2%; their HHI is 1020, a lower bound whose floor falls in the diversified range without classifying the omitted tail.

How much carbon products and insulators does the U.S. import?

$1.3B of customs value in 2025, with $224.1M in USITC Calculated Duties — an effective calculated-duty rate 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).

Tariff monitor · Electrical & Wiring

Carbon Products and Insulators: Statutory & Effective Tariff Rates

USITC Column 1 General rates for 13 carbon products and insulators HTS lines (parseable range 0%–4.6%). Effective rate Jun 2026: 14.46%; monthly history since 2014.

The short answer

The observed effective calculated-duty rate on U.S. imports of carbon products and insulators was 14.46% in Jun 2026, down from 18.04% a year earlier — USITC Calculated Duties divided by covered customs value. The Column 1 General line-rate range is 0%–4.6% across 13 HTS lines in the 2026 schedule; individual lines are called “Free” only when the official General field is literally Free, which still does not determine a shipment’s final duty. 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 a parseable Column 1 General range of 0%–4.6% in the 2026 schedule. “Free” means the official General field is literally Free for that line; it does not determine final entry liability.

Observed calculated-duty data

Latest month on record (2026-06): 14.46% effective on $130.2M of imports, versus 18.04% in the same month a year earlier. The monthly archive holds 150 observations from 2014-01 through 2026-06.
In 2025, U.S. imports for consumption in this family totaled $1.3B in customs value, with $224.1M in USITC reported calculated duty on $1.3B of covered customs value: an effective calculated-duty rate of 17.8%. The aggregate reflects the recorded entry mix but does not attribute the result to a specific legal provision.
A year earlier the effective calculated-duty rate was 6.63%, so the observed rate 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%).
Reported freight and insurance equaled 5.27% of covered customs value in 2025 ($55.3M total); charge coverage was 83.2% of customs value, from USITC DataWeb. It is shown alongside the effective calculated-duty rate and is not part of the customs-value duty base.
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? USITC calculated duties imply an effective rate of 14.46% in Jun 2026 (calculated duties ÷ covered customs value, USITC DataWeb). The parseable Column 1 General line-rate range is 0%–4.6%; individual lines are called “Free” only when the official General field is literally Free, and product, origin, preference and tariff mix can contribute to the observed-rate difference.
What are the statutory MFN line rates for carbon products and insulators? The parseable Column 1 General line-rate range is 0%–4.6% across the family's 13 eight-digit HTS lines in the 2026 Harmonized Tariff Schedule (headings 8545, 8546, 8547). “Free” means the official General field is literally Free for a line; it does not determine final entry liability.
Which countries supply the most carbon products and insulators to the U.S.? Top retained sources in 2025: China ($277.1M at 49.95%), Mexico ($167.7M at 3.2%), India ($144.3M at 15.35%). China holds 22% of total family import customs value. Retained sources cover 83.2%; their HHI is 1020, a lower bound whose floor falls in the diversified range without classifying the omitted tail.
How much carbon products and insulators does the U.S. import? $1.3B of customs value in 2025, with $224.1M in USITC Calculated Duties — an effective calculated-duty rate 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. MFN-Free and Special-rate fields describe statutory line coverage only; final entry liability requires origin, date, eligibility, exclusions and other transaction facts. Calculated Duties are statistical estimates, not a cash-collections ledger. Confirm classification, origin, program eligibility, and final entry liability with a licensed customs broker.

Last reviewed 2026-08-31.