Powder Coated Aluminum from China: AAMA, QUALICOAT and GB/T 5237.4 for Buyers
What the AAMA 2603/2604/2605 and QUALICOAT specifications, China's GB/T 5237.4-2017 standard, common coating tests and the US duty scope say for buyers of powder coated aluminum profiles from China, with a link to each source.
How to read this guide
Not legal or engineering advice. This guide lists the public coating specifications, test methods, Chinese national standard and US duty scope that come up when buying powder coated aluminum profiles from China. Each statement links to the page it comes from. Confirm the requirements for your project with your specifier, test lab and customs broker.
It does not name or rank manufacturers and does not quote prices, minimum orders or lead times; ask each supplier for those in writing.
US specifications: AAMA 2603, 2604 and 2605
AAMA 2603, 2604 and 2605 describe test procedures and performance requirements for pigmented, high performance and superior performing organic coatings on aluminum extrusions and panels, a "good – better – best" set with increasing minimum coating thickness. Source: FGIA, "Start 2023 with the most recently updated FGIA standards and documents".
All three test color uniformity, specular gloss, dry film hardness, film adhesion, impact resistance, chemical resistance, corrosion resistance and resistance to color fading due to weathering. Source: FGIA, "Start 2023 with the most recently updated FGIA standards and documents".
In the 2022 editions, humidity and salt spray exposure increases from 1,500 hours (2603) to 3,000 hours (2604) to 4,000 hours (2605), and outdoor weathering from one year to five years to ten years. Source: FGIA, "Start 2023 with the most recently updated FGIA standards and documents".
On May 19, 2026, FGIA released AAMA 2605-26, together with AAMA 2603-26 and 2604-26; FGIA says the update adds guidance on pretreatment conversion coatings and that the three were last updated in 2022. Source: FGIA, "FGIA Updates Suite of Finishes Documents for Aluminum Extrusions, Panels" (May 19, 2026).
The FGIA online store lists AAMA 2605-26 as the active edition. Source: AAMA 2605-26, FGIA online store.
European label: QUALICOAT
QUALICOAT classifies organic coating materials by their performance in outdoor exposure in Florida: Class 1 one year, Class 1.5 two years and Class 2 three years. Source: QUALICOAT Specifications, 26th Edition, Vol. 3 (Specifications for Powder Manufacturers), Table 2.
The 26th edition of the QUALICOAT specifications for powder manufacturers is valid from 2026-01-01. Source: QUALICOAT Specifications, 26th Edition, Vol. 3 (Specifications for Powder Manufacturers), Table 2.
In the 2024 QUALICOAT specifications, the minimum powder coating thickness is 60 µm for Classes 1, 1.5 and 2, 50 µm for Class 3, 110 µm for two-coat powder coating (Classes 1 and 2) and 80 µm for two-coat PVDF powder coating, measured to ISO 2360 at no fewer than five measuring areas. Source: QUALICOAT Specifications 2024, Master Version V01b, §2.3.
Because the label covers a licensed coating plant and approved coating materials, ask which plant applied your coating and which approved material was used.
China's national standard: GB/T 5237.4-2017
GB/T 5237.4-2017 covers wrought aluminium alloy extruded profiles for architecture, Part 4: powder coating profiles; it was published on 2017-10-14, has been in force since 2018-05-01 and is current. Source: GB/T 5237.4-2017 record, National Public Service Platform for Standards Information.
It fully replaces GB/T 5237.4-2008, and its last periodic review, on 2025-07-01, concluded that it remains valid. Source: GB/T 5237.4-2017 status record, National Public Service Platform for Standards Information.
It applies to electrostatically powder coated architectural profiles using thermosetting polyester, polyurethane or FEVE powders and thermoplastic PVDF powder. Source: GB/T 5237.4-2017 scope, National Library of Standards.
If a supplier quotes GB/T 5237.4, ask for the test results for your lot and, separately, for any AAMA or QUALICOAT results your project requires.
Test methods that appear in coating reports
Thickness. ASTM B244 uses eddy-current instruments for the nondestructive measurement of the thickness of a nonconductive coating on a nonmagnetic basis metal. Source: ASTM B244-09(2021), Scope and Significance and Use.
Adhesion. ASTM D3359 assesses the adhesion of relatively ductile coating films to metallic substrates by applying and removing pressure-sensitive tape over cuts made in the film. Source: ASTM D3359-23, Scope and Significance and Use.
ASTM D3359 evaluates whether adhesion is adequate for the user's application but does not distinguish between higher levels of adhesion. Source: ASTM D3359-23, Scope and Significance and Use.
Salt spray. ASTM B117 describes the apparatus, procedure and conditions of the salt spray test but does not prescribe the specimen, exposure period or interpretation of results for a product. Source: ASTM B117-19, Scope and Significance and Use.
ASTM B117 notes that prediction of performance in natural environments has seldom been correlated with salt spray results used as stand-alone data. Source: ASTM B117-19, Scope and Significance and Use.
US duties: powder coated extrusions
The US countervailing duty notice on aluminum extrusions from China states that extrusions that are finished, for example anodized, liquid painted or powder coated, stay inside the scope. Source: Federal Register 91 FR 51662, FR Doc. 2026-16362 (Aug. 11, 2026), case C-570-968.
The notice states that the written description of the scope is dispositive, not the HTSUS number. Source: Federal Register 91 FR 51662, FR Doc. 2026-16362 (Aug. 11, 2026), case C-570-968.
For rates and reviews see the anti-dumping guide, and confirm classification with your customs broker before you order.
Checklist before you place an order
These steps follow from the sources above.
- Write the coating specification and edition (for example AAMA 2604 / 2605, a QUALICOAT class or GB/T 5237.4) into the purchase specification.
- Ask for test results tied to the coating system actually applied to your profiles.
- Ask how and where coating thickness was measured.
- If you ask for salt spray results (ASTM B117), require the exposure hours and evaluation criteria in the report.
- Confirm the US duty scope with your customs broker if you import into the US.
- Check the factory's registration with the factory check tool and model duties with the landed-cost calculator.
FAQ
What is the difference between AAMA 2604 and AAMA 2605? AAMA 2605 is the most stringent of the three; in the 2022 editions its humidity and salt spray exposure is 4,000 hours versus 3,000 for 2604, and outdoor weathering is ten years versus five. Source: FGIA, "Start 2023 with the most recently updated FGIA standards and documents".
What minimum thickness does QUALICOAT Class 2 powder coating require? 60 µm in the 2024 QUALICOAT specifications. Source: QUALICOAT Specifications 2024, Master Version V01b, §2.3.
Is GB/T 5237.4-2017 still current? Yes. The National Public Service Platform for Standards Information lists it as current, in force since 2018-05-01. Source: GB/T 5237.4-2017 record, National Public Service Platform for Standards Information.
Are powder coated aluminum extrusions from China covered by US duties? Yes. The US countervailing duty notice states that powder coated extrusions stay inside the scope. Source: Federal Register 91 FR 51662, FR Doc. 2026-16362 (Aug. 11, 2026), case C-570-968.
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