I. Tariff Composition
What determines the tariff composition?
Based on U.S. practices regarding tariffs on China, the composition is understood as follows: **Total Formula**—Final Tariff = Base Rate (MFN rate) + Section 301 Tariff (if on the list) + Section 232 Tariff (if on the list) + Anti-dumping/Countervailing Duties (if applicable) + Fentanyl Tariff (20%) + Reciprocal Tariff (10%) (Source: CCPIT Certificate of Origin Declaration System); **New Section 301**—New Section 301 tariffs imposed by the U.S. on 60 countries and regions starting July 24, 2026 (replacing the Section 122 tariffs—at rates of 10% or 12.5%—that expired on July 24; Source: Sichuan Provincial Department of Commerce); **Stacking**—New Section 301 tariffs are levied cumulatively with old Section 301 tariffs (Section 232 tariff rates range from 25% to 50%; Source: Sichuan Provincial Department of Commerce); **Reciprocity**—As of November 10, 2025, all goods from China/Hong Kong face a 10% rate plus an additional 10% IEEPA reciprocal tariff, totaling 20% (Source: U.S. CBP Tariff Overview); **No Exceeding**—The U.S. has stated that tariffs on China will not exceed 20% (Source: Sichuan Provincial Department of Commerce); **Half**—The additional tariffs imposed by the U.S. on China primarily consist of Section 301 tariffs, covering nearly half of Chinese exports to the U.S.—mostly non-sensitive products (rates range from 7.5% to 100%, with the vast majority between 7.5% and 25% and a few reaching 100%; Source: Ningxia CCPIT). In summary, the composition involves six key aspects: the total formula, New Section 301, cumulative application of new and old tariffs, the 20% reciprocal tariff, the 20% cap, and the scope covering nearly half of the goods.
II.
Section 301 Tariffs
What to look for regarding Section 301 tariffs.
Here is a breakdown of the Section 301 tariffs across six key aspects: **12.5%**—An additional 12.5% tariff applies to imports from mainland China, Hong Kong, Vietnam, and over 30 other economies (this is levied in addition to existing Section 301 tariffs but does not stack with tariffs imposed under Section 232 on products such as steel, aluminum, copper, automotive parts, timber, and semiconductors; source: CCPIT Sichuan); **Ad Valorem**—The US imposes an additional 12.5% ad valorem tariff on relevant products from mainland China and Hong Kong (source: Hong Kong Trade and Industry Department); **60 Economies**—The Section 301 tariffs apply to products from 60 economies (including mainland China and Hong Kong) starting July 24, 2026 (source: Hong Kong Trade and Industry Department); **Tiered Approach**—For the EU and Taiwan, the additional tariff applies if the original Most-Favored-Nation (MFN) rate is below 10%; no additional tariff is imposed if the MFN rate is already 10% or higher. For Japan, South Korea, and Switzerland, the combined rate (Section 301 tariff + MFN rate) reaches 12.5% if the original MFN rate is below 12.5%; no additional tariff is imposed if the MFN rate is already 12.5% or higher (source: CCPIT Sichuan); **Combined Rate**—For Japan, South Korea, and Switzerland, the Section 301 tariff is set to bring the total rate to 12.5% when the MFN rate is below 12.5% (if the MFN rate is 12.5% or higher, the Section 301 tariff is 0%); the 12.5% rate applies to all other investigated economies, including mainland China and Hong Kong (source: CCCME); **Exemptions**—Seven categories of products are eligible for exemption (a product exemption mechanism is included in these measures; source: CCCME). Understanding these six points—the 12.5% tier, ad valorem rate, 60 economies, tiered rules, combined 12.5% rate, and seven exemption categories—provides a clear picture of the Section 301 measures.
III.
Section 232 Tariffs
Key aspects of Section 232 tariffs: Scope—Products subject to Section 232 tariffs primarily include steel and aluminum products and their derivatives, passenger vehicles, light trucks, and automotive parts (Sichuan Provincial Department of Commerce, April 2025); Rates—Section 232 tariff rates range from 25% to 50% (Sichuan Provincial Department of Commerce); Formula—For products within the Section 232 scope (steel, aluminum, copper, automobiles, and parts), the final tariff = Base Rate (MFN rate) + 25% to 100% (Section 232 tariff) (Zhejiang CCPIT); Stacking—Tariffs under the new Section 301 and Section 232 for products such as steel, aluminum, copper, automobiles and parts, timber, and semiconductors are not cumulative (Sichuan CCPIT); Base Rate—The MFN (Most-Favored-Nation) rate applied by the US to Chinese goods typically ranges from 0% to 10%, varying by product (e.g., approx. 12% for apparel, approx. 3% for electronic components; Sichuan Provincial Department of Commerce, April 2025); Machinery—HTS Chapter 84 Machinery (Chapter 84 covers nuclear reactors, boilers, machinery, and mechanical appliances and parts; HTS 8407 spark-ignition engines: MFN 2.5%, Sec 301 25%; 8408 compression-ignition engines: Free, Sec 301 25%; 8409 internal combustion engine parts: 2.5%, Sec 301 25%; 8411 turbojet engines: Free; TariffsTool)—Six key points for Section 232: steel/aluminum/automobiles; 25%–50% rates; 25%–100% formula; no stacking with Section 301; MFN 0%–10%; and Chapter 84 machinery rates—a clear overview of Section 232.
IV.
Inquiry Methods
What to look for in inquiry methods: Official Website—The official site for checking US tariffs is the HTS code lookup system of the US International Trade Commission (USITC) (URL: https://hts.usitc.gov/); Code—China’s HS code and the US HTS code for the same product may differ (the first 6 digits are identical, but subsequent digits vary; therefore, you must first determine the US HTS code for your product); HTS—The HTS code is a 10-digit classification system for US goods established by the USITC (the first 6 digits generally align with the HS code, while the last 4 digits provide further refinement; my country’s customs codes are also 10 digits, established by the General Administration of Customs, with the first 6 digits largely matching the US HTS code but the last 4 digits differing); Ministry of Commerce—If the US HTS code is unknown, you can search via the Ministry of Commerce website (URL: https://wmsw.mofcom.gov.cn/wmsw/); Example—To check the latest tariff for the product “planing, milling, or cutting machines for working wood or similar materials” (HTS code 8465.92.00), enter 8465.92.00 into the search bar; Data—The US HTS is based on the international Harmonized System (HS) (a global commodity nomenclature applicable to most world trade in goods; hts.usitc.gov). Summary of six key points: USITC official site, identical first 6 digits, 10-digit HTS, Ministry of Commerce lookup, 8465.92.00 example, and HS-based system—this six-point approach makes the inquiry feasible.
V.
Calculation Considerations
What to look for regarding calculation considerations.
When calculating tariffs for exporting non-standard assembly lines to the US, consider the following six key aspects: **Stacking**—New and old Section 301 tariffs are levied cumulatively (for products covered by both, Final Tariff = Base Rate [MFN] + 7.5%–100% [Old 301] + 12.5% [New 301]); **Non-stacking**—For products covered by the new Section 301 tariffs but not the old ones, Final Tariff = Base Rate [MFN] + 12.5% [New 301]; **Section 122**—For products not covered by Section 301 or Section 232 tariffs (the majority of products fall into this category), Final Tariff = Base Rate [MFN] + 10% [Section 122 Tariff]; **Goods in Transit**—Exemptions apply to goods in transit (specifically those actually loaded for final shipment before midnight, US Eastern Time, on July 24); **Lookup Method**—The first six digits of the US HTS code match the HS code (enter the first six digits of the Chinese HS code; the left-hand search results will display detailed HTS codes for selection based on the specific product); **Dynamic Adjustments**—Tariff policies change, so monitor the latest announcements (e.g., Section 301 investigation results, reciprocal tariff reductions).
Ensure clarity on these six points: stacking of new/old tariffs, exclusion from old Section 301, the 10% Section 122 tariff, transit exemptions, six-digit code lookup, and dynamic adjustments.
Conclusion
Regarding the tariffs for exporting non-standard assembly lines to the US, the conclusion is that the assessment is based on five dimensions: tariff composition, Section 301 tariffs, Section 232 tariffs, lookup methods, and calculation considerations.
Composition of the final tariff: MFN base rate + Section 301 tariffs (if on the list) + Section 232 tariffs (if on the list) + anti-dumping/countervailing duties (if applicable) + 20% fentanyl tariff + 10% reciprocal tariff; new Section 301 tariffs (effective July 24, 2026) imposing an additional 10% or 12.5% on 60 countries and regions, replacing the 10% tariff under Section 122; new Section 301 tariffs applied cumulatively with existing Section 301 tariffs; Section 232 tariff rates ranging from 25% to 50%; and an additional 10% tariff on all goods from China/Hong Kong.
IEEPA: Combined tariff rates total 20%; the US has stated that tariffs on China will not exceed 20%. Section 301 tariffs cover nearly half of Chinese goods exported to the US (rates range from 7.5% to 100%, with the vast majority between 7.5% and 25%). Regarding the additional 12.5% levy: it applies to mainland China, Hong Kong, Vietnam, and over 30 other economies (the new Section 301 levy stacks with the old Section 301 but does not stack with Section 232 tariffs on steel, aluminum, copper, auto parts, timber, and semiconductors); an additional 12.5% ad valorem duty is imposed on goods from mainland China and Hong Kong; implementation for 60 economies begins July 24, 2026; tiered rules apply (levy applies only if the original MFN rate is below 10%; the combined Section 301 and MFN rate is capped at 12.5%); for Japan, South Korea, and Switzerland, if the MFN rate is below 12.5%, the combined rate is raised to 12.5%, whereas if the MFN rate exceeds 12.5%, the Section 301 levy is 0%; seven categories of products are eligible for exemptions. Section 232: Tariffs primarily cover steel and aluminum products (and their derivatives), passenger vehicles, light trucks, and auto parts; rates range from 25% to 50%; the final tariff for Section 232 products equals the MFN rate plus 25%–100%; these do not stack with Section 301 tariffs; base MFN rates are typically 0%–10% (e.g., ~12% for apparel, ~3% for electronic components); examples include Chapter 84 machinery—such as HTS 8407 spark-ignition engines—subject to a 2.5% MFN rate plus a 25% Section 301 levy. Inquiry: Official US inquiry website—USITC.
Consult the HTS system at hts.usitc.gov; while the first six digits of the Chinese HS code and the US HTS code for the same product are identical, the subsequent digits differ, so the specific US HTS code must be determined. The HTS code consists of 10 digits: the first six align with the HS system, while the last four provide detailed classification. If the HTS code is unknown, it can be looked up via the Ministry of Commerce platform (wmsw.mofcom.gov.cn)—for instance, searching for planing, milling, or cutting machines for wood and similar materials under code 8465.92.00. Note the following tariff structures: for products falling under both “old” and “new” Section 301 lists, the final tariff is MFN + Old 301 (7.5%–100%) + New 301 (12.5%); for products only on the “new” Section 301 list, it is MFN + 12.5%; for products not subject to Section 301 or 232 measures, it is MFN + 10% (Section 122 tariffs, applicable to the majority of products). Exemptions exist for goods in transit (shipped before midnight, US Eastern Time, on July 24).
Input the first six digits of the Chinese HS code to find the corresponding US HTS code, and monitor the latest announcements for dynamic tariff policy adjustments.
In summary, regarding US export tariffs: start with MFN rates, add Section 301 duties, check for Section 232 steel/aluminum measures, and use HTS codes for verification—master these four steps, and tariff compliance is assured.
