Technical and procurement guide · 11 August 2026
PPGI Steel Coil Procurement Checklist: What to Specify Before You Request a Quote
A buyer-facing RFQ framework for prepainted galvanized steel coil: substrate, metallic coating, paint build, color, forming, inspection, packing and delivery.
Answer first
The short answer
A PPGI steel coil inquiry should not stop at color, thickness and width. For comparable offers, state the end use and exposure, applicable substrate and prepainted-sheet standard, steel grade or forming class, zinc coating designation, base-metal thickness, paint system, primer/top/back-coat build, color and gloss reference, surface or film requirement, coil geometry, processing route, inspection evidence, packing and destination. ASTM A755 treats the metallic substrate, organic coating and forming method as combined determinants of finished-product performance; the acronym PPGI alone does not define outdoor life or system compliance.
Technical explanation
What controls the result
ASTM A755/A755M covers metallic-coated sheet that is prepainted by coil coating for exterior building products. It identifies zinc-coated, aluminum-zinc alloy-coated and aluminum-coated substrate categories, while the ordered product must still state the applicable substrate requirement and coating system.
EN 10169:2022 addresses continuously organic-coated steel flat products and their technical delivery conditions. It covers coil, sheet, slit strip and cut lengths; project exposure and national provisions remain part of selecting coating performance.
ECCA's EN 13523 overview distinguishes test methods for coating thickness, gloss, color difference, bend cracking, humidity and condensation resistance. A named paint resin is not an inspection plan: agree the relevant test method, acceptance rule and approved sample before production.
Decision table
PPGI steel coil RFQ: the order fields that make supplier offers comparable
| Order control | State in the RFQ | Verify before shipment |
|---|---|---|
| Substrate | Applicable metallic-coated sheet standard, steel grade/forming class, zinc designation and base-metal thickness | Mill certificate, coating designation and thickness measurement basis |
| Paint system | Pretreatment, primer, top/back coat, dry-film thickness, color standard, gloss and protective film | Approved sample, coating data and agreed appearance checks |
| Conversion | Coil width, ID/OD, mass, camber/edge requirement, roll-forming or bending duty and cut-length plan | Coil geometry, labels, edge condition and any agreed processing tolerance |
| Project and delivery | Exposure, profile or panel use, quantity, packing, moisture protection, destination and delivery date | Packing list, dry-storage protection, batch identification and inspection dossier |
A coating system does not prove roof, wall or deck capacity, water tightness, fire performance or a project warranty without the approved assembly, design and installation details.
Selection workflow
From service to an auditable specification
Start with the installed product and exposure: roof, wall, internal liner, appliance or other formed use; record UV, moisture, industrial or coastal conditions and design-life assumptions.
Specify substrate, metallic coating and organic coating as separate requirements. Do not use PPGI, PE, SMP, HDP or PVDF as the entire order description.
Agree an approved color and appearance reference, coating build, relevant EN 13523 or project test methods, and the acceptance route for scratches, bends and cut edges.
Release the full coil quantity only after the supplier confirms the exact order schedule, sample/document approval, packing method and destination-handling requirements.
Limitations
What this guide cannot decide alone
- This checklist supports sourcing and comparison; it does not select the finished building-envelope assembly, establish corrosion life or replace local design, fire, wind, water or warranty requirements.
- Paint family, zinc designation, nominal thickness and coil price cannot be used alone to compare corrosion performance or service life across different environments and fabrication details.
Procurement checklist
Make supplier offers comparable
End use, installed environment, project location and required service basis
Substrate standard, steel grade/forming class, metallic coating designation and base-metal thickness
Paint system, primer/top/back coat, dry-film thickness, color reference, gloss and protective film
Width, thickness, coil ID/OD, unit mass, edge, flatness and processing requirements
Inspection documents, sample approval, test methods, marking, packing, moisture protection and destination
Evidence
Sources and review
Project specifications and the current governing editions supersede this general guide.
ASTM International · A755/A755M-18(2024); ordered edition controls
BSI · Technical delivery conditions
European Coil Coating Association · EN 13523 test-method overview
Attributable sourcing request
Turn your PPGI requirement into a comparable coil inquiry
Send the end use, environment, substrate and zinc designation, base-metal thickness, paint build, color, dimensions, processing need, quantity and destination. We will organize the inquiry so suppliers quote one defined requirement.