What certification to an international weld procedure actually involves

"Certified welder" is one of the least precise phrases in industrial recruitment. It is used to mean anything from has completed a welding course to holds a current qualification, to a named standard, on a defined procedure, within a stated range of validity. The distance between those two meanings is the distance between a candidate who passes on arrival and one who does not.

This article describes what the second meaning involves. It describes the discipline generally; it does not publish the parameters of any specific weld procedure, for reasons set out at the end.

The standard: BS EN ISO 9606-1:2017

BS EN ISO 9606-1:2017 is the international standard for the qualification testing of welders in fusion welding of steels. Two features of it are frequently misunderstood.

The first is that it qualifies the welder, not the weld and not the procedure. A separate discipline — welding procedure qualification — establishes that a given set of welding parameters produces a sound joint in a given material. Welder qualification testing establishes something different: that this particular person can execute that established procedure to the required quality, with their own hands, on the day.

The second is that a qualification is bounded. It is not a general licence to weld. It is valid within a defined range: the process used, the material group, the thickness range, the joint and product configuration, the welding position, and the consumable and shielding arrangements. A welder qualified in one range is not thereby qualified in another. A qualification is also time-limited and subject to continuity of practice — it can lapse.

Any conversation about a "certified welder" that does not state the range is incomplete. The right question is never are they certified? but certified to what, in what range, and is it current?

The controlled procedure

Before a candidate touches a test piece, the test itself has to be fixed. This is the role of the weld procedure specification: a document that states, in advance, the exact conditions under which the test will be performed.

Fixing it in advance does two things. It makes the test comparable — every candidate assessed against the same procedure has been asked the same question, so their results can be set against each other and against the requirement of the receiving yard. And it makes the test honest — because an assessor who cannot alter the requirement cannot quietly soften it to accommodate a candidate who is struggling, or harden it against one they have doubts about.

This is why, in a properly run assessment system, procedure parameters are read-only to assessment staff. The assessor's authority is to record what happened. It is not to determine what was required. Where conditions on the day genuinely depart from the procedure, the correct response is to write the deviation into the record — not to absorb it silently and issue the result as though nothing had changed.

Material grade and thickness

The procedure specifies material grade because different steels behave differently under heat. Their response to the thermal cycle, their susceptibility to cracking, their preheat and interpass requirements, and their tolerance of a given heat input all vary with composition. Qualification on one material group does not automatically transfer to another, which is why the standard groups materials rather than treating steel as a single substance.

Thickness matters for a related reason, and it is one of the most commonly misunderstood points in welder qualification. Thickness governs the thermal mass of the joint: how quickly heat is drawn away from the weld pool, how many passes are required, and how the weld behaves as it cools. A welder who can produce a sound joint on thin material is not thereby demonstrated to be able to produce one on heavy section, where multi-pass technique, interpass control and the discipline of consistent bead placement across many passes all come into play.

The qualification therefore carries a thickness range, derived from the thickness actually tested. Not a general competence in "welding steel".

Process and consumable control

The welding process — the specific method by which the arc, the filler and the shielding are delivered — is a distinct manual skill in each case. Torch angle, travel speed, arc length, manipulation and the sensory feedback the welder is reading all differ between processes. Competence in one is genuinely not competence in another, and the standard treats them separately for that reason.

Consumable control is the part most often skipped in informal testing, and it matters more than its low profile suggests. The filler material and the shielding arrangement are part of the metallurgy of the finished joint, not accessories to it. Substituting an equivalent-looking consumable, or allowing shielding conditions to drift, changes the chemistry and mechanical properties of the deposited weld metal. A test performed with an uncontrolled consumable has not tested the procedure; it has tested something adjacent to it.

The same applies to storage and handling of consumables, to polarity, and to the shielding arrangement itself. Each is specified rather than assumed, and each is part of what makes the test result mean something.

Non-destructive examination

The final discipline is the one that decides the outcome, and it is where visual judgement stops being sufficient.

A weld can look entirely acceptable from the outside and contain defects that would cause it to fail in service. Lack of fusion between passes, internal porosity, slag inclusions, root defects, cracking beneath the cap — none of these are reliably visible on the surface. Non-destructive examination exists precisely to detect what the eye cannot: examination methods that interrogate the interior of the joint without cutting it apart, applied to acceptance criteria defined in advance.

This is the point at which "looks like a good welder" and "is a qualified welder" separate. Examination is not a formality appended to a test that has already been passed by eye. It is the test.

The examination result belongs in the record alongside the practical result, because the two answer different questions and a partner reviewing the file will want both.

The record

A qualification that cannot be audited is an assertion. The record behind a defensible certification should identify, at minimum: the procedure reference the candidate was tested against; the standard framing it; the test piece reference; the assessor; the date; the practical result; the non-destructive examination outcome; and any deviation recorded on the day. Where a candidate has attempted a stage more than once, earlier attempts remain in the record rather than being overwritten by the successful one.

That last point is worth stating plainly, because it is where most informal certification quietly fails. A record that can be edited after the fact is not evidence. It is a document. The value of the audit trail lies precisely in the fact that no one — assessor, recruiter or manager — can go back and improve it.

Why the specific parameters are not published here

We do not publish the parameters of our own weld procedures. This is not opacity for its own sake. A trade test whose exact conditions are published in advance becomes a rehearsal, and a candidate coached to one published configuration has demonstrated preparation rather than competence. The parameters are disclosed where they belong: to the assessor performing the test, to the partner's quality function reviewing the evidence, and in the record attached to the individual worker's file.

What can be said in public is the discipline: an international standard, a controlled procedure fixed in advance, defined material and thickness, controlled process and consumables, independent examination, and a record that survives scrutiny afterwards. A certification produced under those conditions means something to a yard that has never met the assessor. One produced without them does not.

Sources

• BS EN ISO 9606-1:2017 — Qualification testing of welders, fusion welding, Part 1: Steels.