TECHNICAL 18 · QUALITY
What a third-party inspector asks for, in the order they ask.
An inspection is usually a pre-shipment visit with a checklist. Knowing the checklist in advance is the difference between a clean pass and a week of rework at the port.
| Step | Inspector checks | Document |
|---|---|---|
| 1 | PO vs mill certificate: grade, heat numbers | Mill cert (EN 10204 3.1 or 2.2) |
| 2 | Quantities vs packing list | Packing list |
| 3 | Dimensions: length, holes, bend | Drawing + tolerance sheet |
| 4 | Coating thickness at defined points | Coating certificate |
| 5 | Visual: bare spots, welds, cut ends touched in | Photo record |
| 6 | Bundle integrity, edge protection, lashing points | Loading plan |
| 7 | Marking: bundle ID, member ID, orientation marks | Marking scheme |
| 8 | Fittings count and packing | BOM |
Steps 1, 4 and 7 are where most findings are raised.
The three findings that actually occur
- Coating missing at cut ends or welds — because the PO said the coating class but not the process.
- Marking absent or illegible — because the marking scheme was never agreed.
- Fittings short — because a carton was counted as a bundle or packed loose.
Who pays for the inspection
Normally the buyer, and it is worth it on a first order. On repeat orders with a stable specification it is often reduced to a photo report. We accept third-party inspectors on site and will supply the documents in advance so the visit is inspection, not document collection.
What we will not do
We will not issue a certificate we are not entitled to issue, and we will not describe a reference configuration as a certified design. If an inspector asks for a design certificate, it comes from your engineer.
Questions this page answers
What coating do you use?
Pre-galvanised Z275 coil for roll-formed members, or hot-dip after fabrication to ISO 1461 where the project specifies it.
Is Z275 the same as hot-dip?
No. Z275 is a coil mass designation, about 20 μm per side, and cut ends are bare. Hot-dip coats the finished part including cut ends and welds.
Can I inspect before shipment?
Yes, in our works, and we will issue documents in advance. Third-party inspectors are welcome; the cost is yours.
What certificate do I get?
Mill certificate per heat number (EN 10204 2.2 or 3.1 as agreed), plus a coating certificate. We do not issue design certificates.
What tolerance do you hold?
Cut length ±2 mm, hole position ±1.5 mm, bend ±5 mm over the arc, squareness ±3 mm per metre. Tighter on request, quoted separately.
What if something is wrong on arrival?
Photograph it, mark the bundle, and send us the photo with the bundle ID. We replace or credit per the agreed terms; we do not ask you to prove it twice.
Do you have ISO 9001?
We will state exactly what we hold and what we do not, in writing, rather than imply a certificate. Ask for the current certificate and check the scope and the expiry date yourself.
Are your certificates current?
Some of our certificates have expiry dates that have passed, and we do not present them as current. Ask which are valid today and we will answer with dates.
Read next
Pages that answer the question this page raises.
- 08.17Drawing tolerancesGreenhouse frame fabrication tolerances: cut length, hole position, bend radius, squarenes→
- 09.04Quality controlGreenhouse frame quality control: incoming coil, dimensional checks, coating inspection, b→
- 08.21Customs documentsGreenhouse frame export documents: commercial invoice, packing list, mill certificate, bil→
- 08.06Zinc coating standardsZinc coating standards for greenhouse steel: Z275 mass coating, ISO 1461, ASTM A123 and GB→
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