Factory audit checklist for steel structure suppliers

What a factory audit should prove

A steel structure factory audit should answer more than "does the supplier have a workshop?" For EPC procurement, the audit should prove whether the supplier can produce the required tonnage, control quality during fabrication, document the work, pack components for export, and communicate issues before they become site delays.

The checklist below can be used for an on-site visit, video audit, or document-based prequalification.

1. Company and project experience

• Business license and registered company name.
• Years of steel structure fabrication experience.
• Recent projects with similar tonnage and building type.
• Export project experience and destination markets.
• Reference photos, delivery records, or project summaries.

Ask for examples that match your project. A supplier that only shows small sheds may not be suitable for a large industrial package.

2. Workshop and equipment check

Review whether the production equipment supports your member types and schedule.

3. Capacity and schedule verification

A supplier may state a high annual capacity but still be unable to reserve enough production space for your package. Ask for the current production schedule and available capacity during your required window.

• Monthly output under normal production conditions.
• Peak monthly output with overtime or added shifts.
• Current backlog and committed orders.
• Material procurement lead time.
• Expected production sequence for your package.

4. Material traceability

Traceability matters when the owner, EPC contractor, or inspector asks for proof that the fabricated components match the specified material. The audit should review how the supplier receives, stores, marks, cuts, and records steel material.

• Incoming material certificate review.
• Material storage and separation by grade.
• Heat number or batch tracking method.
• Material transfer from raw steel to cut parts.
• Certificate submission format for the project file.

5. Welding quality control

Welding quality should be controlled before final inspection. Ask how the supplier manages weld procedures, welder qualification, in-process inspection, and repairs.

• Welding procedure specifications or internal welding process documents.
• Welder qualification records, if required by project standards.
• Visual inspection process.
• NDT requirements and subcontracted inspection process if applicable.
• Repair record and approval process.

6. Coating and corrosion protection

For export projects, coating damage can happen during handling, packing, sea freight, and site unloading. Confirm the coating process and the inspection records available.

• Surface preparation grade.
• Primer, intermediate coat, topcoat, or galvanizing requirements.
• Dry film thickness measurement method.
• Paint batch records and color confirmation.
• Touch-up and repair process before packing.

When coating is a critical package risk, review the steel structure coating line audit checklist before final supplier approval.

7. Documentation audit

Ask the supplier to show sample documents before the order. The sample does not need to be from your project, but it should prove that the supplier can prepare the required record type.

• Material certificate package.
• Inspection report template.
• Welding inspection record.
• Coating inspection record.
• Packing list and component marking list.
• Container loading photo sample.

8. Audit scoring method

For shortlisted suppliers, use a consistent scoring method.

Buyer follow-up questions

How should buyers use this page?

Use it as a practical review aid for factory audit checklist for steel structure suppliers. The page helps the buyer confirm what must be checked, what evidence should be requested, and which follow-up actions should be closed before the package moves to the next procurement step.

When should this review happen?

Use it before supplier award, especially when price, capacity, document control, and delivery claims need to be compared on the same basis.

What evidence should be kept?

Keep the records that prove the decision, especially capacity evidence, quotation assumptions, audit findings, quality-document discipline, export packing experience, and schedule realism. Photos, comments, approvals, open issues, and closeout notes should stay linked to the relevant drawing, supplier reply, shipment, or handover record.