Start with four product questions
ECCA's selection guidance starts from end-use requirements: forming severity, outdoor exposure, scratch risk, chemical or temperature conditions and intended appearance all affect product choice. Because prepainted aluminium is finished before fabrication, bending, roll forming, punching, laminating and bonding belong in the RFQ.
| Question to answer | Specification decisions it drives |
|---|---|
| What is the finished part and how is it made? | Alloy and temper, gauge, forming direction, bend or draw requirement, protective film and first-piece trial |
| Which face is visible and what happens to the back? | Front colour and gloss, backcoat, bonding or lamination compatibility and surface protection |
| Where will it be used? | Indoor or outdoor exposure, moisture, UV, chemicals, cleaning and cut-edge treatment |
| What result counts as acceptable? | Reference sample, test method, measurement points, sampling, tolerance and exception workflow |
RFQ input table: what the buyer should state
BS EN 1396:2023 provides a specification framework for coil-coated aluminium sheet and strip for general applications, covering dimensions, coating properties, testing, inspection and delivery. The project parties still need to confirm its scope, edition and the ordered product class.
| Field | Information to provide or ask the supplier to confirm |
|---|---|
| Application and fabrication | Finished use, processing steps, visible face, forming direction, minimum bend requirement, bonding materials and service environment |
| Aluminium substrate | Alloy, temper and mechanical-property basis; if open, provide load, forming and corrosion needs for technical selection |
| Dimensions and coil build | Nominal gauge, width, tolerances, edge condition, inside diameter, outside diameter or maximum coil weight, plus equipment limits |
| Coating stack | Pretreatment, front primer/topcoat, backcoat, function of each face, resin or performance class and dry-film measurement boundary |
| Appearance reference | Colour system or physical master, gloss, texture, viewing light/angle and coil-to-coil consistency rule |
| Inspection evidence | Applicable standard, named test methods, sample locations, acceptance values, retained sample, batch identity and shipment documents |
| Commercial and logistics | Sample or trial quantity, batch volume, delivery window, destination, moisture/handling limits and trade term |
Do not separate a target from its measurement method
‘Film thickness compliant’, ‘colour matched’ and ‘formable’ are incomplete acceptance clauses. BS EN 13523-1:2024 provides several dry-film methods whose readings on textured coatings can represent average, maximum, minimum or total thickness. BS EN 13523-3:2024 links colour difference to illuminants and metamerism. State the specimen, instrument or method, locations, calculation and tolerance together.
| Requirement | Measurement boundary to add |
|---|---|
| Colour | Physical master or colour reference, illuminant, measurement geometry, colour-difference equation, tolerance and metamerism requirement |
| Gloss | Measurement angle, instrument, texture, target and tolerance; priority when the master and number disagree |
| Dry-film thickness | Face or layer, method, calibration, number of locations, average/minimum rule and edge exclusion |
| Forming and adhesion | Material direction, specimen temperature, bend or cross-cut method, viewing/tape conditions and crack or delamination criterion |
Five steps from enquiry to batch release
- The buyer sends the application, fabrication, environment, dimensions, appearance reference, quantity and delivery constraints, marking open decisions explicitly.
- The supplier returns each item as confirmed, proposed deviation, trial required or not confirmed, with assumptions recorded in a technical-deviation list.
- Both sides freeze the specification revision, master sample, test methods and first-piece criteria; appearance-sensitive orders use an identified physical master.
- Validate forming, bonding, laminating or cleaning with target material and the actual or representative process, recording material direction and conditions.
- Release production lots against the agreed sampling and evidence; reassess changes to substrate, paint, colour, tooling or a critical process.
Qihao perspective: a good RFQ makes technical unknowns visible
From a coil-coating and process-communication perspective, RFQs that trigger repeated sampling are not always the shortest ones. Some contain fixed paint names, film builds or tolerances that have never been checked against the end use, while leaving the fabrication route and failure concerns unstated. Separating ‘mandatory’, ‘supplier to propose’ and ‘trial required’ makes the document more executable.
Qihao recommends including a part sketch, visible face, forming direction, physical colour master, equipment coil-diameter and weight limits, and the principal failure concern in the first technical review. The supplier can then return a material proposal, deviations and a validation plan instead of pricing only a colour and tonnage.
This is a Qihao observation based on public standards information, industry guidance and general manufacturing experience. It is not a promise of alloy, coating performance, delivery or compliance for a particular order. The signed specification, master samples and inspection records remain controlling.
Scope boundary: a template does not replace application validation
This checklist supports general prepainted aluminium coil and sheet enquiries. Building envelopes, food or hygiene contact, severe corrosion, fire performance, long-term exterior exposure, electrical uses and other regulated applications may require dedicated product standards, regulatory documents and independent tests. Do not copy one sector's test list into another without review.
Where alloy, temper or coating system is open, provide the real manufacturing and service conditions for review by the material, paint, fabricating and end-use parties. Standard methods align test language; they do not alone prove that an untested process will work with a specific lot.
Sources
- BS EN 1396:2023 Aluminium and aluminium alloys — Coil coated sheet and strip for general applications — SpecificationsBritish Standards Institution · 2023
- BS EN 13523-1:2024 Coil coated metals — Film thicknessBritish Standards Institution · 2024
- BS EN 13523-3:2024 Coil coated metals — Colour difference and metamerismBritish Standards Institution · 2024
- Choosing the Right Prepainted Metal ProductEuropean Coil Coating Association · Accessed 12 August 2026
- Prepainted metal for designersEuropean Coil Coating Association · Accessed 12 August 2026
Frequently asked questions
What information is essential in a prepainted aluminium RFQ?
At minimum: finished use and environment, fabrication route, alloy and temper or required properties, gauge and width, coil geometry limits, front and back functions, colour/gloss reference, quantity, destination and intended acceptance evidence. Mark open fields for supplier recommendation.
Is a RAL colour enough to release production?
A RAL or other colour reference is a useful starting point, but coating system, lighting, texture and measurement geometry affect appearance. For appearance-critical work, agree a physical master, gloss, viewing and measurement conditions, colour tolerance and coil-to-coil rule before release.
Is citing EN 1396 enough for a complete specification?
No. The product standard supplies a framework. The order still needs the applicable edition and class, dimensions, coating and appearance requirements, named test methods, sampling and acceptance values. Forming, bonding and service conditions also require application validation.
Why does a supplier need coil ID and maximum coil weight before quoting?
Inside diameter, outside diameter and coil weight affect production, slitting, packing, handling and whether the buyer's line can load the coil safely. Stating equipment and lifting limits early avoids a technically suitable strip that cannot be used on site.
Related product and technical review
This article provides general information. Product availability and application-specific performance require technical confirmation.