Sheet metal fabrication in China

China leads; alternatives compete. China supplied 28.1% of US imports of HS 7326.90 steel articles in 2025, down from 40.8% in 2018, while Mexico rose to 18.3% and India to 5.2% (UN Comtrade).

Is China still the default source for sheet metal fabrication?

China is still the largest single source, but not by the margin it once held. Sheet metal fabrication is the work of turning flat metal sheet into finished parts such as enclosures, brackets, chassis and panels by cutting, forming, joining and finishing it, and in the closest US trade proxy China's share has fallen by about a third since 2018.

That proxy is HS 7326.90, other articles of iron or steel. US imports under it were US$5.25 billion in 2025, down from US$6.49 billion in 2024, according to UN Comtrade, the United Nations trade database. China supplied 28.1%, Mexico 18.3%, Canada 9.5%, India 5.2%, Germany 4.7%, Taiwan 3.5% and Vietnam 2.8%. In 2018 China supplied 40.8%, Mexico 13.0%, India 2.6% and Vietnam 1.6%. The proxy is partial: enclosures, brackets and chassis are often classified by function, for example as parts of chapter 84 or 85 machines.

The verdict on this page is "China leads; alternatives compete." Fabricated steel and aluminum articles are squarely inside Section 232 at 50% of full value for most chapter 73 and 76 codes, and that duty applies to every origin. China's remaining lead therefore rests on cost and speed, not on tariff position.

How sheet metal fabrication works

Sheet metal fabrication has four stages, and the volume of the order decides how the second one is done.

• Cutting by fiber laser, by turret punch (a CNC punch press with a rotating turret of tools) or by waterjet.
• Forming on a press brake for bends, or by progressive die stamping for high volume, in which a die with several stations cuts and forms a metal strip in sequence.
• Joining by MIG, TIG or spot welding, by riveting, or with PEM-type self-clinching fasteners pressed into the sheet.
• Finishing by powder coat, zinc plating, anodizing, or passivation for stainless steel.

Common materials are cold-rolled steel, galvanized steel, stainless steel, aluminum and copper. Low volumes run on laser and press brake with no hard tooling. High volumes move to stamping dies, which bring a tooling ownership question similar to plastic molds.

The work runs from drawing and flat-pattern review (bend allowances and K-factor, the ratio that locates the neutral axis in a bend) through material procurement, cutting and forming, welding and hardware, finishing (often subcontracted), inspection and FAI, packaging and freight. Stamped parts add die design, build and tryout. No official source gives durations for these stages, so none are stated here.

Tooling ownership and how quotes are built

For sheet metal parts cut by laser and bent on a press brake there is little or no tooling charge. Price is driven by material, cut length, number of bends, welds, hardware inserts, finishing and packaging.

Stamping carries a one-time die charge plus a piece price. Die cost depends on the number of stations, the die steel, the strip layout and the expected die life. As with molds, the common model is buyer title with the tool kept at the parts producer (USITC Pub. 3556, 2002), and the purchase agreement should state title, exclusive use, a removal right and a nameplate on the die.

Steel and aluminum sheet prices follow index prices, and quotes often include a material adjustment clause. Since 6 April 2026, Section 232 is assessed on full customs value, the price actually paid for the goods, so the fabrication labor and finishing are dutiable at the same rate as the metal.

Drawings, tolerances and quality documents

Sheet metal tolerances depend on the process. Laser-cut profiles hold tighter than bend-to-bend dimensions, and stack-up across several bends is the usual source of rejects. Untoleranced dimensions should default to a named general standard such as ISO 2768-m. Flatness and weld distortion must be called out explicitly, and the drawing should state bend radius and grain direction.

• FAI (First Article Inspection) and a CMM or vision-system report.
• Mill certificates for the sheet, showing grade, thickness and, for galvanized steel, coating weight.
• Coating tests: powder-coat thickness and adhesion, plus salt-spray reports where specified. A coating specified by color alone, without thickness, salt-spray hours and pretreatment, invites a dispute.
• Weld procedure documentation, and PPAP for automotive programs.

Mill certificates also carry tariff weight. Section 232 rates turn on the country where the steel was melted and poured and the aluminum smelted and cast: Proclamation 11021 sets a 10% rate for articles of US metal and a 200% rate for Russian aluminum. Current CBP reporting instructions for those fields were not re-checked for this page.

Tariff exposure as of October 2026

The governing instrument is Proclamation 11021 (91 FR 18201), effective 6 April 2026. It applies Section 232 duty to the full customs value of listed articles, regardless of metal content, and sorts them into annexes. Annex I-A is the list at 50%, Annex I-B the list at 25%, and Annex III a temporary list at a 15% combined rate through 2027.

The steel-rack entry shows how quickly scope moved for sheet metal products. The exact statistical suffixes after Proclamation 11032 were not confirmed, so the current annex should be checked for the specific code.

• No low-metal exemption for chapter 73. The under-15%-metal exemption under 9903.82.03 does not apply to goods in chapters 72, 73, 74 and 76 (CBP CSMS #68253075, 3 April 2026).
• No forced-labor Section 301 duty on top. The 12.5% duty on products of China from 24 July 2026 exempts articles under the Section 232 metals headings (FR Doc. 2026-15181). A court challenge to that action has been reported in secondary sources.
• Older China Section 301 list duties are the remaining China-specific layer. HTSUS chapter 99 notes generally impose them in addition to Section 232, but list coverage of 7326.90.86.88 in 2026 was not verified here.
• IEEPA duties ended with the Supreme Court's 20 February 2026 ruling in Learning Resources, Inc. v. Trump.

The rate history explains the 2025 import drop. Steel and aluminum duties stood at 25% with exclusions ended from 12 March 2025, rose to 50% on 4 June 2025 (Proclamation 10947, date per a law-firm summary; the Federal Register text was not re-checked), and two inclusion rounds on 18 August and 9 October 2025 added derivatives. The 19% fall in US HS 7326.90 imports from 2024 to 2025 is consistent with that timing; the data do not establish cause. A licensed customs broker should confirm the classification for each part.

Where sheet metal fabrication is shifting

• Mexico rose from 13.0% to 18.3% of US HS 7326.90 imports between 2018 and 2025. USMCA-qualifying goods receive content-based treatment under Annex I-C (Proclamation 11032, effective 8 June 2026).
• India doubled its share, from 2.6% to 5.2%.
• Vietnam rose from 1.6% to 2.8%.

Because Section 232 applies to all origins, with separate treatment for the UK, USMCA-qualifying goods and negotiated partners, and China is not on the 15% preferential list, moving a fabricated steel part to India or Vietnam does not avoid the 50% duty. It avoids the China Section 301 list duties where they apply to the code. Whether India or Mexico is cheaper for a given part is not established by these data.

On cluster geography inside China, no official or academic data on sheet-metal job shops in Dongguan, Suzhou, Ningbo or elsewhere was found.

Common mistakes and how to evaluate a fabricator

• Assuming the under-15%-metal exemption can apply to a chapter 73 article.
• Declaring Section 232 on metal content after 6 April 2026.
• Shipping without melt-and-pour or smelt-and-cast documentation.
• Issuing drawings without bend radius, grain direction or flatness callouts.
• Specifying a coating by color only.
• Leaving ownership of stamping dies unwritten.
• Underestimating packaging and freight damage on large enclosures, which dent and scratch.

Evaluating a sheet metal fabricator turns these into questions. Ask which cutting, forming and welding processes are in-house and which finishing steps are subcontracted. Ask for a sample FAI, a mill certificate for the grade quoted and a coating test report. Ask how the shop handles bend-allowance review on the flat pattern, and request its packaging specification for the part. For stamped parts, get the die ownership terms and expected die life in writing before the die is built.

Frequently asked questions

Sources

• United Nations Statistics Division (UN Comtrade) — UN Comtrade database, reporter USA, flow imports, HS 732690, 2018, 2024 and 2025 (2025, HTML-official)
• Executive Office of the President / Federal Register — Proclamation 11021, Strengthening Actions Taken To Adjust Imports of Aluminum, Steel, and Cop… (2026, PDF)
• Office of the United States Trade Representative — USTR, Notice of Actions in Section 301 Investigations ... Failure ... to Impose and Effectively E… (2026, PDF)
• US Department of Commerce, Bureau of Industry and Security — Adoption and Procedures of the Section 232 Steel and Aluminum Tariff Inclusions Process… (2025, PDF)
• whitehouse.gov/wp-content/uploads/2026/04/ANNEXES-I-A-I-B-II-III-IV.pdf
• whitehouse.gov/wp-content/uploads/2026/06/Annex-III.pdf
• federalregister.gov/documents/2026/06/04/2026-11314/further-adjusting-the-ta…
• content.govdelivery.com/bulletins/gd/USDHSCBP-4117593