How welding qualification ranges are worked out from a test weld
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Short answer
A qualification test weld qualifies a range, not just the tested value. Under AS/NZS 1554.1 a butt weld procedure test qualifies material from 0.5 to 2.0 times the thickness of the thinner test plate (Table 4.11(A) item (o)), and above 36 mm no upper limit applies at all (Clause 4.1.2(k)). Welder qualification is a separate calculation with its own position ranges from Table 4.12.2(A), and the standard states explicitly that the positional limits of the procedure do not apply to the welder. Changing an essential variable outside its band invalidates the qualification and requires a new test.
Key numbers
- Procedure butt thickness range
- 0.5 to 2.0 times the thickness of the thinner test plate (Table 4.11(A) item (o))
- Thick material
- At 36 mm and above, no upper thickness limit applies (Clause 4.1.2(k)(ii))
- Welder pipe diameter range
- Test piece outside diameter of 100 mm or less qualifies d to 2d; above 100 mm qualifies 0.5d to unlimited
- Welder test piece
- Minimum examination length of 300 mm, examined visually and by macro test
- Joint type
- A butt test may cover fillet welds. A fillet test never qualifies butt welds
- Reapproval trigger
- Six months without the relevant process, or a change of employer, or any reason to question the welder
Thickness: procedure and welder ranges are different numbers
The single most common mistake is applying one thickness range to everything. Procedure qualification, welder qualification and deposited weld metal each carry their own band.
For procedure qualification, AS/NZS 1554.1 Table 4.11(A) item (o) uses 0.5 to 2.0 times the thickness of the thinner test plate, and Clause 4.1.2(k) removes the upper limit at 36 mm and above. The full procedure story, including electrical tolerances, lives in the WPS, PQR and WQR guide.
Welder qualification follows its own tables. Do not copy the procedure thickness band onto the welder certificate without checking Table 4.12.2(A) and the test route used.
- Procedure butt welds below 36 mm
- 0.5 to 2.0 times the thickness of the thinner test plate (Table 4.11(A) item (o))
- Procedure butt welds at 36 mm and above
- No upper limit applies (Clause 4.1.2(k)(ii))
- Production weld
- Must fall inside both the qualified procedure range and the welder's approved range
Welder position ranges are not the procedure position ranges
AS/NZS 1554.1 says this outright: the positional qualification limits of the welding procedure are not applicable to welder qualifications. They are separate calculations from separate tables, and treating the procedure position range as the welder position range is a frequent audit finding.
Welder position coverage comes from Table 4.12.2(A), which sets the range of approval by welding position for plates and pipes, butt welds and fillet welds separately. As a general principle position coverage is directional: a more difficult position extends downward to easier ones, but vertical and overhead do not cross-qualify each other, so a shop that welds in both usually tests in both.
Pipe is handled by diameter rather than by position alone, and the rule is unusually generous above 100 mm.
- Pipe test piece, outside diameter 100 mm or less
- Qualifies d to 2d
- Pipe test piece, outside diameter above 100 mm
- Qualifies 0.5d to unlimited
- Hollow sections
- d is the dimension of the smaller side
- Steel type
- A qualification with any one steel covered by the standard qualifies any other steel it covers (Clause 4.12.2.3)
- Automatic and semi-automatic operators
- A qualification with an approved consumable extends to other approved consumables on the same process (Table 4.12.2(B))
Two routes to qualify a welder
Clause 4.12.2.2 accepts welders already qualified under a recognised welder qualification standard, provided the evidence refers to joints and positions as close as practicable to the production work. Welders qualified to AS 1796, AS/NZS 2980, AS/NZS 3992, NZS 4711 or ISO 9606-1 are deemed qualified.
Clause 4.12.2.3 covers everyone else: the welder welds a test piece for the procedures required on the job. The test weld needs a minimum examination length of 300 mm, is examined visually and by macro test, and must satisfy the acceptance levels of Clause 6.2.2. Grinding or repair of the capping passes of a test weld is not permitted, which is worth telling the welder before they start rather than after.
Process and material group are qualified one at a time
A qualification is tied to the welding process used, identified by its ISO process number: 111 for MMAW, 135 for GMAW, 136 for FCAW, 141 for GTAW, 121 for SAW. Some standards allow grouping of related processes, but that grouping is never automatic and ForgeQM does not apply it silently. If a shop moves from 135 to 136, that is a new qualification question, not a paperwork detail.
Material group works the same way. AS/NZS 1554.1 covers carbon and carbon manganese steels; quenched and tempered steels fall under AS/NZS 1554.4 and stainless under AS/NZS 1554.6. ForgeQM blocks a 1554.1 qualification from being applied to stainless or quenched and tempered material unless an override is recorded with a reason.
Essential variables invalidate procedure support, not just the welder card
A production weld needs a procedure that still covers every essential variable, and a welder whose approved range covers the joint. Step outside either and the qualification no longer supports the weld.
Electrical tolerances are process dependent. Under AS/NZS 1554.1 Table 4.11(A), current is plus or minus 15% for MMAW and GTAW, and plus or minus 10% for SAW, GMAW and FCAW. The full procedure EV list is in the WPS, PQR and WQR guide.
- Current
- Plus or minus 15% for MMAW and GTAW; plus or minus 10% for SAW, GMAW and FCAW
- Voltage
- Plus or minus 15% for MMAW and GTAW; plus or minus 7% for GMAW, FCAW and SAW
- Travel speed
- Plus or minus 15%
- Preheat
- A decrease of more than 20 degrees C below the qualified value
Reapproval is the part registers usually miss
Welder qualifications are not permanent, and AS/NZS 1554.1 Clause 4.12.2.4 lists three separate triggers for reapproval. Only the first is the familiar continuity rule.
The second trigger surprises people: for welders not qualified to AS/NZS 2980, NZS 4711 or ISO 9606-1, changing employer invalidates the qualification, and the new employer has to qualify the welder again. A shop that hires an experienced welder and files their previous in-house certificate has not met the standard.
A register that stores only the issue date cannot see any of this, so it will show qualifications as current when they are not. ForgeQM tracks continuity alongside the certificate so a lapse is visible before the weld is made rather than during an audit.
- Six months or more have elapsed since the welder was employed on the relevant welding processes
- The welder changes employment, unless they are qualified to AS/NZS 2980, NZS 4711 or ISO 9606-1
- There is some specific reason to question the welder’s ability
Frequently asked questions
What thickness does a 12 mm test plate qualify under AS/NZS 1554.1?
For butt weld procedure qualification, a 12 mm test qualifies 6 mm to 24 mm, being 0.5 to 2.0 times the thickness of the thinner test plate under Table 4.11(A) item (o). If the coupon joined 12 mm to 20 mm, the range is still measured from the 12 mm member. Note that the upper limit only exists below 36 mm: a 36 mm or thicker test has no upper limit under Clause 4.1.2(k)(ii).
Do welder position ranges follow the welding procedure position ranges?
No, and AS/NZS 1554.1 says so explicitly in a note to Clause 4.12.2.3: the positional qualification limits of the weld procedure are not applicable to welder qualifications. Welder position coverage comes from Table 4.12.2(A), which treats plates and pipes, and butt and fillet welds, separately. Reading the procedure range onto the welder is a common and avoidable finding.
Does a welder qualification survive a change of employer?
Only if the welder was qualified to AS/NZS 2980, NZS 4711 or ISO 9606-1. For any other route, AS/NZS 1554.1 Clause 4.12.2.4 requires reapproval when the welder changes employment, and it puts that obligation on the new employer. The other two reapproval triggers are six months or more without the relevant process, and any specific reason to question the welder’s ability.
Does a butt weld qualification cover fillet welds?
Usually yes, subject to conditions in the governing standard, because a butt weld is the more demanding test. The reverse is never true: a fillet weld qualification does not qualify butt welds, since it demonstrates neither full penetration nor the same tensile and bend performance.
Do qualification ranges differ between AS/NZS 1554, ISO 15614 and ASME IX?
Yes, and they are not interchangeable. Each code sets its own essential variables and range rules, so a procedure qualified to ASME IX is not automatically acceptable under AS/NZS 1554.1. ForgeQM digitises the AS/NZS 1554 series as hard gates. ASME IX is supported as an essentials checklist rather than a full QW-451 range engine, and AWS D1.1 is advisory, so those ranges must still be confirmed by a welding coordinator.
Sources
This guide is written against the published standards below. Standards are revised, and project specifications override general guidance, so confirm clause numbers against the edition your contract names before relying on them.
- AS/NZS 1554.1:2011 Structural steel welding, Part 1: Welding of steel structuresTable 4.11(A) item (o) thickness essential variable, Clause 4.1.2(k) thickness limitations including the 36 mm rule, Clause 4.12.2 welder qualification routes, Table 4.12.2(A) range of approval by welding position, Clause 4.12.2.4 reapproval.
- AS/NZS ISO 9606-1 Qualification testing of welders, Fusion welding, Part 1: SteelsOne of the welder qualification standards accepted under Clause 4.12.2.2, alongside AS 1796, AS/NZS 2980, AS/NZS 3992 and NZS 4711.
- AS/NZS 1554.4 and AS/NZS 1554.6Quenched and tempered steel, and stainless steel scope boundaries that AS/NZS 1554.1 does not cover.
- ISO 4063 Welding and allied processes, Nomenclature of processes and reference numbersThe ISO process numbers (111, 121, 135, 136, 141) used to scope a qualification to a process.
Related guides
- WPS vs PQR vs WQR: What Each Record ProvesA PQR records a test weld and its results, a WPS turns that evidence into welding instructions with qualified ranges, and a WQR proves an individual welder can work to it. Written order, what carries between them, and the AS/NZS 1554.1 ranges.
- Weld NDT Requirements and Inspection ExtentsVisual scanning is always 100%. Beyond that, NDT extent comes from the governing standard, the weld category or construction class, and the material. AS/NZS 1554 structural rules and a compact AS 4037 class table, with method selection logic.
- Heat Input, Carbon Equivalent and Preheat FormulasArc energy and heat input are not the same number. The heat input formula with EN 1011-1 thermal efficiency factors, IIW carbon equivalent and Pcm, and how AS/NZS 1554.1 Clause 5.3.4 combines them with combined thickness to give a preheat temperature.
Stop checking this by hand
ForgeQM applies the AS/NZS 1554 series as checks while you write the record, not after. Qualification ranges are generated from the PQR, NDT extents come back with the clause they came from, and job data carries across every document through to the MDR.
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