HS code 840991 tariff rate
Suitable for use solely or principally with spark-ignition internal combustion piston engines (including rotary engines):
HS 840991
Suitable for use solely or principally with spark-ignition internal combustion piston engines (including rotary engines):
Current US base rate (structured schedule)
Free
Rates vary by line: Free, 2.5%
Effective date
No dated action in the last 30 days. The base rate above stands until a new action takes effect.
Duty stack summary
- Base rate (MFN): varies by line (Free, 2.5%).
- Additional duties noted: none on these lines in the structured schedule.
- Recent trade actions: none in the last 30 days of scanned notices touches this category.
Summary
HS 840991 covers suitable for use solely or principally with spark-ignition internal combustion piston engines (including rotary engines):. The structured schedule lists a base rate of 2.5% on most lines in this category. No trade action in the last 30 days of scanned notices touches this category. Confirm the classification of your specific goods with your broker.
What this rate means for an importer
No single base rate covers this category. Lines carry different rates, shown in the table below.
The base rate is only the starting point. Extra duties from trade actions sit on top of it and change more often than the base schedule. Before you set a price or sign a purchase order, run the code through the free lookup to see recent actions.
Tariff lines in this category
Showing 12 of 16 lines. Match your goods to the closest line.
| Line | Base rate | Goods |
|---|---|---|
| 8409.91 | See schedule | Suitable for use solely or principally with spark-ignition internal combustion piston engines (including rotary engines)... |
| 8409.91.10 | Free | Cast-iron parts, not advanced beyond cleaning, and machined only for the removal of fins, gates, sprues and risers or to... |
| 8409.91.10.40 | See schedule | For vehicles of subheading 8701.21, 8701.22, 8701.23, 8701.24 or 8701.29, or heading 8702, 8703 or 8704 |
| 8409.91.10.60 | See schedule | For marine propulsion engines |
| 8409.91.10.80 | See schedule | Other |
| 8409.91.30.00 | 2.5% | Aluminum cylinder heads |
| 8409.91.50 | 2.5% | Other |
| 8409.91.50.10 | See schedule | Connecting rods |
| 8409.91.50.81 | See schedule | Steel forgings |
| 8409.91.50.85 | See schedule | Other |
| 8409.91.92 | 2.5% | For marine propulsion engines |
| 8409.91.92.10 | See schedule | Connecting rods |
More in HS chapter 84 (Machinery and mechanical appliances)
Nearby codes: 840681 840682 840690 840910 840999 841011 841012
Nearby chapters: Chapter 83 - Chapter 85
HS 840991 questions
What is the US base rate for HS 840991?
No single rate covers this category. Lines carry different rates: Free, 2.5%, listed in the table on this page. Match your goods to the closest line and confirm it with your broker.
Does the base rate tell the full story for HS 840991?
No. Extra duties from trade actions can sit on top of the base rate and change often. Use the free lookup to see recent actions for this code before you commit to a price.
Where does this rate come from?
The base rate comes from the structured US tariff schedule, read through the Tariff Wire HS lookup. Recent actions come from published Federal Register notices from the last 30 days. Each lookup links its official source.
Can I use this page to classify my goods?
No. This page covers the HS-6 product category. The exact 8 or 10 digit classification of your goods, and what you owe on a specific entry, is work for you and your licensed customs broker.
How do I get an alert if the rate for HS 840991 changes?
Tariff Wire Pro watches this category every day and sends one plain-English alert when a change touches it, with the official source linked. That monitoring is part of the paid plan.
Check the live rate for HS 840991
Schedules change. Run this code through the free lookup to see the current base rate and any recent trade actions.
Look up HS 840991Get an email the day this rate changes
Monitoring is part of Pro. Sign up once and Tariff Wire watches HS 840991 for you every day, with the official source linked in each alert.
Get alerts for HS 840991General information only, for educational and planning purposes. This is not legal advice and not a customs classification determination for your specific goods or entries. Tariff classification of your products should be confirmed with your licensed customs broker. Rates shown as 'detected' are taken from official notice text and are not confirmed; rates shown as 'confirmed' come from structured HTS data, which updates days to weeks after legal effective dates. Last updated 2026-09-28 from the structured US tariff schedule. Rates change; confirm with your broker before you act.