ISO 3834 Welding Quality
EN 15085 Welding Compliance
EN 1090 Welding Compliance

Best Standard for Fusion Welding Quality Control: Why ISO 3834 Is Required for EN 1090 & EN 15085

By First Welding Certification Technical Editorial Team

6 Min Read

12-Sep-2026

Table of Contents

How Manufacturers Achieve Welding Compliance Under EN 1090 & EN 15085

01
Define Applicable Requirements
02
Qualify Welding Procedures
03
Control Welding Production
04
Build Objective Evidence
05
Verify Before Assessment
06
Demonstrate Compliance
iso 3834 certification

A manufacturer can make a weld that looks perfect and still fail an EN 1090 or EN 15085 check.

The reason is simple: welding is a process. You cannot judge the quality of a weld by looking at the finished joint. The manufacturer must control how the welding is done, from the start to the end. This includes the welding procedure the people doing the work the materials used the equipment, inspection methods and records kept during production. This is where ISO 3834 quality requirements for fusion welding become important. ISO 3834 gives a structure for managing welding quality. EN 1090 and EN 15085 use these welding controls within steel and aluminium manufacturing and railway manufacturing respectively.

Why ISO 3834 Matters in Welding Quality Control

ISO 3834 is not another certificate to put on a company website. It sets out the quality requirements for controlling fusion welding of metal materials.

The important question is therefore not:

“Can our welders make welds?”

The better question is:

“Can we show that every weld made during production followed a controlled and approved process?”

An effective welding quality system includes:

  • Welding Procedure Specifications (WPS)
  • Welding Procedure Qualification Records (WPQR)
  • Welder qualifications
  • Welding coordination
  • Base-material identification
  • Welding consumable control
  • Equipment maintenance and calibration
  • Pre-weld, in-process and final inspection
  • NDT records where needed
  • Weld traceability
  • Nonconformity and repair records

ISO 3834 gives the structure to manage these activities of just depending on final inspection.

ISO 3834 and EN 1090: What Manufacturers Must Control

ISO 3834 is not another certificate to put on a company website. It sets out the quality requirements for controlling fusion welding of metal materials.

The important question is therefore not:

“Can our welders make welds?”

The better question is:

“Can we show that every weld made during production followed a controlled and approved process?”

An effective welding quality system includes:

  • Welding Procedure Specifications (WPS)
  • Welding Procedure Qualification Records (WPQR)
  • Welder qualifications
  • Welding coordination
  • Base-material identification
  • Welding consumable control
  • Equipment maintenance and calibration
  • Pre-weld, in-process and final inspection
  • NDT records where needed
  • Weld traceability
  • Nonconformity and repair records

ISO 3834 gives the structure to manage these activities of just depending on final inspection.

ISO 3834 and EN 15085: What Is Actually Mandatory?

This is where manufacturers often get confused.

For EN 15085 the ISO 3834 requirements must be used according to the manufacturers classification level. EN 15085-2 specifies the ISO 3834 requirements based on the classification level, including ISO 3834-2 for CL1 ISO 3834-3 for CL2 and ISO 3834-4 for CL3.For EN 15085, the applicable ISO 3834 quality requirements must be implemented as part of the welding quality system. However, a separate ISO 3834 certificate is not automatically required. The ECWRV guidance provides the technical interpretation used within the EN 15085 certification framework.

However a separate ISO 3834 certificate is not always needed for EN 15085.

The manufacturer must show that the requirements are met through evidence, documents and controlled welding activities. 

This difference is important.

  • For an EN 15085 manufacturer:
  • ISO 3834 certificate: Not automatically needed.
  • ISO 3834 requirements: Needed within the EN 15085 welding system.

So a railway manufacturer should be ready to show:

  • welding quality level
  • Qualified welding coordinator
  • Qualified welders
  • Approved WPS and supporting WPQR
  • Control of materials and consumables
  • Inspection and testing
  • Weld traceability
  • Welding records
  • Control of nonconforming welds
  • Proof that production followed the set procedures

Contractual requirements can also change this. If a customer or tender asks for an ISO 3834 certification the manufacturer must meet that condition.

Documents Auditors Expect to See

One of the issues for welding manufacturers is having the needed documents at the time of production.

An auditor might ask for a WPS then quickly ask:

Which WPQR qualifies it?

Next:
Which welder did this weld?
Then:
Which material was used?

Finally:
Where is the inspection or NDT evidence?
If the answers are in separate spreadsheets, files or emails tracking becomes hard.

A better system creates one record.
For a welded piece keep:

Drawing/Weld ID → WPS → WPQR → Welder Qualification → Material Certificate → Consumable Record → Inspection/NDT → Final Approval

This approach also helps avoid using a welder qualification, incorrect WPS revision or unknown material.

Recent industry talks are more about weld-level traceability, digital weld maps and audit-ready records because missing links between weld IDs, WPS revisions, welder IDs and inspection results are still audit problems.

Practical Difference Between EN 1090 and EN 15085

Think of the standards from the manufacturer’s point of view:

  • EN 1090 is about the production and quality of steel and aluminum parts including Factory Production Control and the welding needs for the chosen Execution Class.
  • EN 15085 is focused on welding companies that make railway vehicles and parts with requirements based on classification and safety importance.

The main difference is the certification path.

  • For EN 1090 the applicable ISO 3834 quality level is a required part of the EN 1090 production framework.
  • For EN 15085 the company must follow the ISO 3834 requirements. A separate ISO 3834 certificate is not always needed.

Common Manufacturer Mistakes

Before an inspection check these five points:

1. WPS. Production uses a different version.
2. Welder certificates. The range does not match the actual work.
3. WPQR. Is not properly connected to the WPS.
4. Material certificates. Traceability is lost after cutting or building.
5. Inspection records. Cannot be connected to specific welds.

These issues often cause audit problems than the actual welding.

Frequently Asked Questions

Is ISO 3834 required for EN 1090?

Yes. The applicable ISO 3834 level is a must for EN 1090 welding according to the Execution Class. EXC1 EXC2, EXC3 and EXC4 each match ISO 3834 levels.

Not automatically. EN 15085 needs the right ISO 3834 requirements to be used. A separate ISO 3834 certificate is only needed if a contract or project asks for it.

The classification level decides the needed level: CL1 uses ISO 3834-2 CL2 uses ISO 3834-3 and CL3 uses ISO 3834-4..

No. They are part of the proof. The company also needs proper welding coordination, qualified workers, material control, inspections, equipment management, traceability and production records.

Good work alone does not show that welding was properly controlled. Auditors need proof that qualified procedures, skilled workers, controlled materials and inspection steps were actually used.

Conclusion

ISO 3834 should not be seen as paper just before an audit. It gives the welding quality system that helps manufacturers show how each weld was planned, made, checked and recorded.

  • For EN 1090 the right ISO 3834 quality level is part of the required welding process.
  • For EN 15085 the company must use the ISO 3834 requirements but a separate ISO 3834 certificate is not always needed.

The real goal is not just getting certificates. It is building a welding system where every important decision has proof behind it.

Related Resources

Ready to improve your welding compliance?

If your company makes steel, aluminum parts or railway welded items start by checking your WPS/WPQR link, welder skills, welding coordination, material traceability, inspection records and document control against the right standard.

For certification rules and specific assessment paths look at the First Welding Certification Pvt Ltd (PRVÁ ZVÁRAČSKÁ, a.s.) certification for EN 1090, EN ISO 3834 and EN 15085.

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