Dengtai fixed ladder installed on building exterior — factory installation

Five-Stage Inspection

Quality Control -
Five-Stage Inspection

Incoming MTC to pre-assembly final check. ISO 5817 Level C welding, ISO 1461 HDG, QC records kept 10 years — every stage documented, every report free.

OSHA 1910.27 BS 4211 EN ISO 14122-4 AS 1657 Full DoC & MTC

Every Order, Every Time

Five-Stage Inspection Process

A fixed ladder passes through five QC gates before it is packed. Each gate produces a record that ships with the order and stays on file for 10 years.

  1. 1

    Incoming Material

    Raw Steel Verified Against MTC

    100% of incoming steel is checked against the purchase order and the mill Material Test Certificate — chemical composition, mechanical properties, dimensions and surface. Accepted against GB/T 700, ASTM A36 or EN 10025.

    Record: MTC traceability sheet
  2. 2

    Cutting & Prep

    First-Piece Full Dimension Check

    CNC plasma or oxy-fuel cutting, sawing, drilling, bending and chamfering. The first piece of every batch is 100% dimension-checked, then sampled — tolerances to ISO 2768-mK.

    Record: dimension report
  3. 3

    Welding & Assembly

    ISO 5817 Level C Visual + PT Sampling

    100% visual inspection of welds per ISO 5817:2014 Level C. A random ≥10% of welds get dye penetrant (PT) testing. Welders hold ISO 9606-1 certificates; procedures qualify per ISO 15614-1.

    Record: weld inspection report
  4. 4

    Surface Treatment

    ISO 1461 HDG or Dual-Coat Paint

    Hot-dip galvanizing to ISO 1461:2022 — local ≥85 μm, average ≥100 μm — with adhesion and uniformity verified. Painted parts get 80 μm zinc-rich primer + 50 μm polyurethane topcoat, adhesion to ISO 2409.

    Record: HDG coating report
  5. 5

    Final Inspection

    Cage-Rail Pre-Assembly & Packing Check

    Cage and rail pre-assembled, full dimension re-check, nameplate verification, then packing inspection — VCI rust protection, vacuum wrap and ISPM 15 fumigated pallets.

    Record: pre-assembly & packing photos

Welding Quality

ISO 5817 Level C Welding

Every rung-to-stringer and bracket weld is inspected to ISO 5817:2014 Level C — the quality level for static, predominantly static structures. That is the level EHS engineers expect for fixed ladder assemblies.

100%
Visual Inspection
≥10%
Dye Penetrant
9606-1
Welder Certs
  • ISO 5817:2014 Level C visual acceptance
  • PT on a random ≥10% of welds per batch
  • Welders certified to ISO 9606-1
  • WPQR qualified per ISO 15614-1
  • Weld records archived with each order file

Corrosion Protection

ISO 1461 Hot-Dip Galvanizing

Galvanizing is done at a certified partner plant 30 km from our factory, with a 14 m bath. The coating is measured, not assumed — thickness readings go into every QC record.

PropertyRequirement
StandardISO 1461:2022
Local coating thickness≥ 85 μm
Average coating thickness≥ 100 μm
AdhesionVerified per ISO 1461
UniformityChecked across full length
ReportCoating thickness sheet shipped free

Traceability

QC Records: Kept 10 Years

If an inspector asks "prove it" three years from now, the file is still there. Every order's QC records — MTC, weld, coating and photos — are archived for 10 years.

Documentation Package

Ships with every order — no extra cost, no paywall.

  • Declaration of Conformity (DoC)
  • Material Test Certificates — EN 10204 3.1
  • Structural Calculations
  • Welding Procedure Specifications
  • Surface treatment certificates (HDG per ISO 1461)
All documents included free with every order.

What "Kept 10 Years" Means

Order-level file

MTC, dimension reports, weld records, coating report and photos bound to the PO.

Reorder traceability

A repeat order can be matched to the original mill certificates for the same material grade.

Audit-ready

Records are inspectable in person or shared on request — that is how factory audits pass.

Why this matters: many platform suppliers ship galvanized ladders with no traceable QC file. Dengtai's five-stage records give your inspector the paperwork to sign off — that is the difference between a ladder and an approved install.

See Before You Buy

Request QC Reports

Ask for a sample QC report from a representative order, or talk to a quality engineer about your acceptance criteria. Reply within 24 hours.

Report Samples Available

MTC 3.1 sample

Mill certificate for Q235B, SS304 or SS316 — chemical and mechanical data.

Weld inspection record

ISO 5817 Level C visual and PT results from a representative order.

HDG coating report

Thickness readings per ISO 1461 across the ladder length.

+86 155 1187 9488

Request QC Report Sample

+ More specifications (height, quantity, cage, standard)
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Quick Answers

Common questions

What are the five inspection stages?

Incoming material (MTC verified), cutting & prep (ISO 2768-mK), welding (ISO 5817 Level C), surface (ISO 1461 HDG), and final pre-assembly.

What welding quality level do you inspect to?

ISO 5817:2014 Level C - 100% visual inspection plus ≥10% dye penetrant testing, by EN ISO 9606-1 certified welders.

How long are QC records kept?

10 years - MTC, weld, coating and photo records are archived per order for inspector audit.

Do QC documents cost extra?

No - DoC, MTC 3.1 and structural calcs ship free with every order.

Can I see a sample QC report before ordering?

Yes - request a sample QC report and we will send a real report from a shipped order.

Project References · 500+ Projects · 50+ Countries

Proven in real facilities

Reference projects are shown by industry, country and scale. Client names are available on request with approval.

National utility projects — 15+ countries

23 documented projects, 2021-2025 · 2025

All standards

Energy & industrial clients — Global

500+ projects since 2004 · 2004-2025

Full compliance docs

Largest single order — Malaysia

60 units in one project · 2021

HDG

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