To get a comparable PPGI coil quotation from your first email, include fourteen fields: substrate and grade, zinc or zinc-alloy coating mass, paint system and topcoat thickness, total coating thickness, colour and RAL reference, surface finish and treatment, coil dimensions, coil weight and ID, tolerances, quantity and delivery schedule, packaging, destination and Incoterms, required standards and test certificates, and commercial terms including a dated quote validity. Leave any one of these out and you invite a supplier to quote a cheaper product against your specification. Three phrases cause most of the damage: “standard coating”, “normal quality” and “best price”. Each one is interpreted differently by every mill, trader and roll former that reads it.
This template is written for importers, roofing-sheet producers, roll formers, procurement managers and engineers sending a first inquiry for prepainted galvanised (PPGI) coil. It distinguishes general industry guidance — the kind of information that is normally useful to state — from contract-specific requirements, which you must confirm against your own project specification, the applicable standard edition and your end customer’s acceptance criteria.
Why the First RFQ Determines Whether Quotes Are Comparable
PPGI is a configured product, not a commodity. Two coils can share the same thickness and colour and still differ in substrate strength, coating mass, paint chemistry, film build, surface treatment and coil geometry. When those variables are unstated, suppliers fill the gaps with whatever is cheapest to produce or easiest to ship. The result is a set of quotations that look competitive on price but describe different products.
A disciplined RFQ does three things. It forces every supplier to price the same configuration. It creates a written record you can attach to a purchase order. And it exposes the gap between a headline price and the price of the coil you actually need. If you are still deciding between coated and uncoated material, the base product pages for PPGI coil and GI coil are useful starting points before you write the specification.
The 14 Mandatory Fields in a PPGI Coil RFQ
1. Substrate and steel grade
State the base metal: hot-dip galvanised steel coil intended for painting, or another metallic-coated substrate. Give the grade designation and the mechanical property you actually rely on — yield strength, tensile strength, elongation, or a formability class for bending and profiling. If the coil will be roll formed into roofing sheets, say so; forming demand affects grade selection more than colour does.
2. Metallic coating mass
Specify the zinc or zinc-alloy coating mass per unit area, both sides, with the test method. “Galvanised” alone tells a supplier nothing about corrosion margin. Coating mass is one of the largest cost drivers in the coil, so an unstated value is an open invitation to quote the lightest coating available.
3. Paint system and topcoat thickness
Name the system: primer type, topcoat chemistry (for example polyester, silicon-modified polyester, polyurethane or PVDF) and whether a back coat is required. Give topcoat and primer film thickness in micrometres, and state whether the figure is nominal or minimum. Paint chemistry determines colour retention, chalk resistance and flexibility — not just appearance.
4. Total coating thickness and test method
State total dry film thickness and the method used to verify it. If you intend to check thickness on incoming inspection, say which instrument principle you will use, so the supplier’s certificate and your verification agree.
5. Colour and reference
Give a colour reference — RAL number, a physical sample, or a master panel — plus the gloss level and whether the finish is solid, metallic or textured. Colour matching across suppliers is only meaningful against a shared reference.
6. Surface finish and treatment
Describe the finish (for example regular, minimum spangle, skin-passed) and any surface treatment such as chromate-free passivation or an anti-fingerprint layer. These details affect paint adhesion and handling, and they are frequently omitted from first inquiries.
7. Coil dimensions
Give thickness, width and any slitting or edge condition requirements. State whether thickness is measured before or after painting, because the paint adds measurable build to the finished coil.
8. Coil weight and inner diameter
State target coil weight or weight range, inner diameter and maximum outer diameter. These values must match your uncoiler, crane capacity and storage. A coil that is technically correct but physically incompatible with your line is still a problem.
9. Tolerances
Specify thickness tolerance, width tolerance, camber, flatness and any crown requirement. Tolerances are a cost variable: tighter limits reduce the number of mills that can supply and usually raise the price.
10. Quantity and delivery schedule
Give total tonnage, number of coils, any call-off or staggered release plan, and the date you need material at destination — not just the date you expect it to leave the mill. Vague timing produces vague commitments.
11. Packaging
State eye-to-sky or eye-to-wall orientation, inner and outer protective wrapping, edge protection, desiccant if required, pallet or skid type, and whether markings must be in a specific language. Packaging protects the paint system, which is the most easily damaged part of the product.
12. Destination, Incoterms and documents
Name the discharge port or final site, the Incoterm and the named place, and the document set you need — for example certificate of origin, mill test certificate, packing list and commercial invoice. Incoterms change the cost structure of every quotation, so they belong in the first email.
13. Standards and test certificates
State the standard you are buying against and confirm the required edition, because editions change and contract values must come from the edition named in your agreement. Ask which tests are routine and which are extra, and whether third-party inspection is expected.
14. Commercial terms and quote validity
Ask for a dated quotation with a stated validity period, payment terms, price basis, and whether the price is firm or subject to raw material adjustment. A dated quote lets you compare offers made in different market conditions on a like-for-like basis.
PPGI Coil RFQ Specification Table
| Field | What to state in the RFQ | Why it changes the price |
|---|---|---|
| Substrate and grade | Base metal type, grade, key mechanical property | Higher strength or tighter forming grades cost more |
| Metallic coating mass | g/m² both sides, test method | Zinc consumption is a direct cost |
| Paint system | Primer, topcoat chemistry, back coat | Resin chemistry drives raw material cost |
| Film thickness | Topcoat and primer in µm, nominal or minimum | More paint, more cost |
| Colour | RAL or sample, gloss level | Special colours and small batches add cost |
| Dimensions | Thickness, width, edge condition | Non-standard widths increase processing loss |
| Coil geometry | Weight range, ID, max OD | Affects handling and logistics |
| Tolerances | Thickness, width, camber, flatness | Tighter limits narrow the supplier pool |
| Quantity and timing | Tonnage, call-offs, required date at destination | Small or rushed lots cost more per tonne |
| Packaging | Orientation, wrapping, edge protection | Export-grade packing is a real cost line |
| Delivery terms | Port or site, Incoterm, named place | Freight, insurance and risk allocation vary |
| Standards and tests | Standard and edition, certificate type | Extra testing and inspection add cost |
| Commercial terms | Payment, price basis, validity period | Terms affect financing and risk pricing |
| Quote validity | Dated offer with expiry | Allows fair comparison across dates |
Treat this table as general guidance. Your project specification, end-use environment and customer contract may require additional or stricter values, and those always take precedence.
The Three Vague Phrases That Break Comparability
“Standard coating”
There is no single industry-wide standard coating. Coating mass and film thickness vary by market, application and supplier. A supplier reading “standard coating” will quote a specification that is defensible for them and possibly inadequate for your roof, façade or appliance panel. Replace the phrase with numbers and a test method.
“Normal quality”
Quality is not a specification. It implies a level of defect acceptance, flatness, colour consistency and coating adhesion that nobody has defined. If you have an acceptance criteria document, attach it. If you do not, describe what the coil must survive: forming operation, bend radius, exposure environment and expected handling.
“Best price”
Asking for the best price without a locked specification guarantees you will receive the best price for the cheapest configuration a supplier can justify. Ask instead for a price against your stated specification, and separately ask what would change if a parameter were relaxed. That gives you a transparent cost ladder rather than a single opaque number.
RFQ Checklist Before You Press Send
- Substrate type, grade and the mechanical property that matters for your process
- Metallic coating mass, both sides, with test method
- Paint system, primer and topcoat chemistry, back coat requirement
- Topcoat and primer film thickness, nominal or minimum
- Colour reference, gloss level, finish type
- Surface finish and surface treatment
- Thickness, width, edge condition, and whether thickness is pre- or post-paint
- Coil weight range, inner diameter, maximum outer diameter
- Thickness, width, camber and flatness tolerances
- Total tonnage, coil count, call-off plan, required date at destination
- Packaging orientation, wrapping, edge protection, marking language
- Destination, Incoterm and named place, required documents
- Standard and edition, test certificates, third-party inspection
- Payment terms, price basis, and a dated quote with validity period
If any line is blank, expect the supplier to fill it with an assumption. Sometimes that assumption is acceptable; often it is not, and you will only discover the difference when the coil arrives.
Common Mistakes in First PPGI Inquiries
- Specifying colour but not film build. Colour is the visible variable; film thickness is the durability variable.
- Omitting the forming operation. A coil destined for a tight bend radius needs different paint flexibility than a flat panel.
- Mixing units. Zinc coating is often quoted in g/m² while paint is quoted in µm. State both clearly and consistently.
- Forgetting the back coat. The reverse side is frequently exposed in roofing and cladding applications.
- Asking for a price without a quantity. Per-tonne economics depend heavily on order size and production scheduling.
- Accepting an undated quote. Coated steel prices move with substrate and coating costs; a quote without a date cannot be compared fairly.
- Assuming a certificate equals a specification. A mill certificate reports results; it does not define what you asked for.
Frequently Asked Questions
How long should a PPGI coil quotation remain valid?
Validity is a commercial term, not a technical one, and it varies with market conditions. Ask each supplier to state a validity period in the offer and to confirm whether the price is firm or adjustable. Then compare offers on the same basis rather than assuming all quotes age equally.
Should I specify zinc coating mass or paint thickness first?
Both matter and they serve different functions. The metallic coating provides the corrosion barrier at cut edges and scribes; the paint system provides the aesthetic and barrier layer. Specify both, and state the exposure environment so the supplier can flag any mismatch.
Can I use one RFQ for several suppliers?
Yes, and you should. A single specification sent to multiple suppliers is the fastest route to comparable quotations. Keep the document identical, and record any clarifications in writing so all suppliers are answering the same question.
What if I do not know the exact standard edition?
State the standard you intend to reference and ask the supplier to confirm which edition they normally work to. Then verify the required edition and the exact contract values with your own technical or quality function before the purchase order is issued.
How do I compare quotes with different Incoterms?
Convert them to a common basis — usually the delivered cost at your named place — before comparing. Freight, insurance, port charges and risk transfer differ significantly between terms, and a lower ex-works figure can be the more expensive option once landed cost is calculated.
Does a lower price always mean lower quality?
Not necessarily, but a materially lower price against an identical specification deserves a question. Ask what differs: coating mass, film build, paint chemistry, tolerance, packaging or payment terms. A supplier who can explain the difference is easier to work with than one who cannot.
Next Step: Send a Specification, Not a Wish
Your first email is the cheapest place to prevent an expensive mismatch. Write the fourteen fields, delete the three vague phrases, and ask for a dated quotation against your stated configuration. If you would like a quotation prepared against a defined PPGI specification, send your completed RFQ through the ChinaCNU contact page, and include any tolerance, packaging or documentation requirements that your project demands. If your inquiry also covers uncoated material, you can reference the GI coil range in the same message so both lines are quoted on consistent terms.
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