How Section 232 steel and aluminum duties apply to Thai-made goods in 2026, including derivative product lists, melt-and-pour rules, exclusions, and how US.

Section 232 Steel & Aluminum Duties on Thai Imports (2026)

Buyers moving metal fabrication to Thailand often budget only the standard MFN duty, then get an unexpected bill because the part falls inside a Section 232 derivative list. Section 232 is a national-security tariff on steel and aluminum, and unlike Section 301 it is not country-specific to China — Thai-origin goods are in scope.

What is actually covered

Section 232 applies to:

Primary steel and aluminum articles (plate, sheet, bar, tube, extrusion, wire).
Derivative articles — finished or semi-finished parts whose value is largely steel or aluminum content. The list has been expanded repeatedly and now reaches many fabricated components, fasteners, brackets, enclosures, and furniture parts.

If your product is mostly metal, assume it is in scope until your customs broker confirms the HTS line is not on a derivative annex. Confirm classification first — see our guide to HTS classification and binding rulings.

Melt-and-pour: where the steel was made matters

For steel, duty exposure follows the country where the metal was melted and poured, not only where the part was machined. A Thai factory that fabricates from imported coil may still trigger the tariff based on the mill origin of that coil.

Ask every quoting factory for:

Mill test certificates (MTC) naming the mill and country.
Whether the coil, billet, or extrusion is domestic Thai, Japanese, Korean, or Chinese origin.
Whether they can commit to a specified mill origin for repeat orders.

For aluminum, the equivalent question is the country of smelt and most recent cast. Factories that cannot answer this are a pricing risk, not a compliance partner.

How the duty stacks

On a metal part the total duty can layer as: MFN rate + Section 232 rate on the metal content value. That means two quotes with the same FOB price can differ materially in landed cost depending on mill sourcing. Run both through the US landed cost formula before you compare.

Reducing exposure legitimately

Specify mill origin in the PO and require MTCs with every shipment.
Report metal content correctly — the tariff applies to the metal value, so an accurate value split, supported by a bill of materials, matters.
Check exclusions: product-specific exclusions exist and are granted per requester and per HTS line. They are narrow and time-limited; do not assume a competitor's exclusion covers you.
Consider design changes where a non-covered material meets the spec, but only with engineering sign-off.
Use an FTZ or drawback where applicable — see duty drawback and foreign-trade zones.

Never mis-declare metal content or origin. This is a high-audit area, and CBP's reasonable-care standard applies to you as the importer of record — see reasonable care and CBP audits.

Practical PO language

Include three clauses in every metal-goods purchase order: (1) supplier warrants mill origin as stated and provides MTCs, (2) supplier indemnifies for duty differences caused by undisclosed mill substitution, (3) any change of mill requires written buyer approval before production.

How TUSKO handles it

We collect mill certificates at the quoting stage, not at shipment, so mill origin is priced into the comparison from day one. Because you contract with TUSKO rather than the factory, a mid-run mill substitution is our problem to prevent and resolve — not a surprise on your entry summary.

FAQ

Does Section 232 apply to goods made in Thailand?

Yes. Section 232 is not limited to China. Thai-origin steel and aluminum articles and listed derivative articles are in scope.

What is the melt-and-pour rule?

For steel, duty exposure is tied to the country where the metal was melted and poured, not only where the finished part was fabricated. Aluminum uses smelt and cast origin.

How do I know if my part is a derivative article?

By HTS classification against the current derivative annexes. Your customs broker or a binding ruling from CBP is the reliable answer; a factory's opinion is not.

Is the duty charged on the whole product value?

Generally on the steel or aluminum content value, which is why an accurate, documented value split and bill of materials matter.

Can I avoid the tariff by machining in Thailand?

Not for steel if the metal was melted and poured in a covered country. Fabrication alone does not reset melt origin.

What should I ask a Thai factory before ordering?

Mill test certificates, country of melt and pour or smelt and cast, whether mill origin can be fixed for repeat orders, and who pays if it changes.