Most Duty-Free HS Chapters: A Census of Where US Tariffs Drop to Zero
Updated October 2026. Every figure below is recomputed from our structured extract of the US Harmonized Tariff Schedule; provenance notes are embedded in the page source.
Ask a room of exporters which US tariff lines are duty-free and most guesses land somewhere between “everything” and “nothing.” The real answer is neither: 1,171 of 3,362 eight-digit rate lines (34.8%) read Free in the general column of the October 2026 schedule — but they are spread across chapters so unevenly that your product’s chapter decides most of the story before you ever pick a code. At one extreme sits iron and steel (chapter 72): 109 of its 112 rate lines — 97% — enter duty-free. At the other, knit apparel (chapter 61): exactly 1 line out of 138 — under 1%. That is a 96-point gap between two chapters of the same tariff schedule, and it reverses the intuition most first-time importers carry. This guide ranks every qualifying chapter by duty-free density and shows where the exceptions hide.
1. Scope and method
We start from the same structured extract used across our census family: 23,193 records from the USITC HTS REST export dated 2026-10-09T17:43:36Z. The schedule writes its binding rate at the eight-digit subheading level; ten-digit statistical suffixes inherit it (we verified inheritance directly: all six statistical children of the lone free knit-apparel line 6104.39.20 are themselves Free, and sampled steel families behave identically). The census therefore counts the 3,362 eight-digit rows, marks a row “duty-free” when its general-column string is literally Free, assigns each row to a chapter by the first two digits of the code, and ranks chapters holding at least 100 such rows — seven chapters qualify. Ranking-table percentages are shown to two decimals.
2. The duty-free density ranking
| Rank | Chapter | Title | Free rows | Eight-digit rows | Duty-free density |
|---|---|---|---|---|---|
| 1 | 72 | Iron and steel | 109 | 112 | 97.32% |
| 2 | 73 | Articles of iron or steel | 75 | 104 | 72.12% |
| 3 | 85 | Electrical machinery and equipment | 82 | 160 | 51.25% |
| 4 | 84 | Machinery, boilers, mechanical appliances | 171 | 343 | 49.85% |
| 5 | 52 | Cotton | 4 | 140 | 2.86% |
| 6 | 62 | Apparel, woven (not knitted) | 3 | 233 | 1.29% |
| 7 | 61 | Apparel, knitted | 1 | 138 | 0.72% |
Chapters with ≥100 eight-digit rate lines, sorted by share of general=“Free” rows. Recompute with python3 scripts/probe_weekly57_duty_free_census.py (keyed output: line P1 is the ranking above).
The table reads as two schedules stapled together. The capital-goods half of the book — metals feeding factories — clusters near or above the halfway mark, with the raw-metal end almost entirely open. The consumer-textiles half sits between 0.7% and 2.9%. Neither the biggest chapters (84 and 85 span 503 lines combined) nor the loudest trade-policy fights explain the extremes; the extremes belong to raw material versus finished good.
3. Inside chapter 72: what is still paid, and why
A 97% free chapter is close to a policy statement: the United States imports most of the steel it consumes as input and prices the value-added step domestically. Only three lines break the pattern, and all three live in one family — ferroalloys, the alloying additives made from mined ores rather than scrap:
| HTS line | Description | General rate |
|---|---|---|
| 7202.30.00 | Ferrosilicon manganese | 3.9% |
| 7202.49.50 | Ferrochromium, other | 3.1% |
| 7202.99.80 | Ferroalloys, other | 5% |
Recompute with python3 scripts/probe_weekly57_duty_free_census.py (keyed output: line P13 lists these three paid lines).
Downstream, the free pass holds: chapter 73, which covers fabricated steel articles, keeps a 72.1% free density (75 of 104) — lower than the raw metal, but still the second-friendliest chapter on the books. The occasional paid line there is a reminder that “steel products” is not one category; check the specific subheading before quoting a landed price.
4. Inside chapter 61: the one line that escapes
Knit apparel’s single free position is 6104.39.20 — “Other”, a residual slot under women’s and girls’ knitted dresses of man-made fibres. Its six ten-digit statistical children are all Free as well, so the escape hatch is real but narrow: a residual basket inside one women’s-wear family, surrounded by 137 paid neighbors.
What do the paid neighbours charge? Of chapter 61’s 138 eight-digit lines, 127 carry a percent rate: the median is 14.6% and the maximum reaches 32%. Woven apparel (chapter 62) is barely softer at a 12.0% median and 28.6% peak, and cotton fabric (chapter 52) splits the difference at 8.8% median — raw fibre and yarn already pay more than pig iron ever will. This is textbook tariff escalation: rates rise with processing depth, so the finished sweater pays for the whole chain. For an exporter, the practical consequence is that in apparel the special column matters more than the general one — our FTA eligibility guide maps which agreements turn those 14–32% rates into zero, and which preference programs pay zero explains the claim mechanics.
5. Below the ranking threshold: small chapters that would medal
The ≥100-line cutoff keeps the ranking honest (no 3-of-4 chapters posing as champions), but it hides some notable small-chapter densities worth knowing: paper and paperboard (chapter 48) is 56 of 56 — completely free; fish and crustaceans (chapter 3) hits 79 of 83 (95%); optical and medical instruments (chapter 90) runs 44 of 53 (83%); furniture (chapter 94) 39 of 65 (60%). None of these overturns the raw-versus-processed pattern — they confirm it from odd angles. And within textiles the band is not uniform either: knitted fabrics (chapter 60) sit at 0 of 26 while raw cotton (chapter 52) manages 2.86%, so the escalation ladder runs inside families as well as between them.
6. Using the census without abusing it
Three boundaries keep this tool honest. First, duty-free density is a screening heuristic, not a rate lookup: a chapter at 97% free still contains paid lines, and the reverse holds for textiles, where one lucky residual does not make a category. Second, the base schedule is not the final bill — chapter 99 layers (Section 301 and friends) attach to listed lines regardless of a Free base, which is why Chinese-origin steel lines marked Free still owe additional duties; our stacked-tariff guide walks the arithmetic. Third, granularity matters: the mirror-image census of the most expensive lines lives at ten-digit resolution in the highest US tariff lines, and the two views bracket the schedule from opposite ends. For the zero-side in absolute terms — lines that are free because of special programs rather than the base schedule — see US duty-free imports: zero-tariff lines.
If you want these numbers as a workflow rather than an article, the free duty calculator resolves any single line in seconds, and the chapter-density table above is reproducible from the public HTS extract with the commands printed beneath each exhibit.
7. Recap
- Steel in, duty-free: chapter 72 posts a 97% free density (109/112); its only paid lines are three ferroalloy positions at 3.1–5%.
- Knits pay: chapter 61 contains exactly one free line (6104.39.20) among 138; median knit duty is 14.6%, peaking at 32%.
- The 96-point spread is tariff escalation made visible — raw inputs near zero, finished consumer goods taxed hard.
- Schedule-wide, 34.8% of eight-digit rate lines are Free; your chapter predicts your starting point better than any average does.