ISO standard · reference card
ISO 10042: scope, quality levels and where it applies
Does ISO 10042 grade the aluminium weld in front of you, or does it belong to ISO 5817 instead? Scope decision flow for arc-welded aluminium joints, the ISO 6520-1 imperfection numbers it shares with the steel route, and where beam-welded aluminium falls outside it.
- Designation
- ISO 10042
- Issued by
- ISO
- Title
- Welding — Arc-welded joints in aluminium and its alloys — Quality levels for imperfections
- Edition
- Confirm the edition your contract cites.
ISO 10042 does for aluminium what ISO 5817 does for steel, nickel and titanium: it grades imperfections into quality levels for arc-welded joints, without telling a reader which level their job needs or whether a given joint passes. That decision sits with the application standard or the contract, exactly as it does on the steel side.
Reading it as a drop-in replacement for ISO 5817 on an aluminium job is the recurring mistake, because the two standards share a reference-number vocabulary — ISO 6520-1 — but are not the same document and are not cross-applicable. A specification calling up the wrong one for the material in front of the welder produces a level structure the joint was never welded to meet.
Aluminium’s welding physics is also why the process side of this standard matters more than it does for steel. High thermal conductivity narrows the practical heat input window and hides overheating from a visual check between passes — the same joint can look correctly welded and still sit outside the interpass band the procedure assumed.
Therness does not grade aluminium welds. The equipment produces the process evidence underneath the grading: measured, not nominal, heat input per pass; non-contact interpass readings where a hand-held check would be too slow or too coarse; and a per-weld trail an auditor can follow. See ISO 5817 for the steel, nickel and titanium route, and ISO 6520-1 for the classification both standards share.
Scope: does it apply to your job?
Applies to
- Arc-welded joints in aluminium and its alloys
- Imperfections already classified under ISO 6520-1
- Quality levels for imperfections, once a contract or application standard selects one
Does not apply to
- Steel, nickel and titanium joints, graded by ISO 5817 instead
- Choosing which quality level a job needs — the application standard or contract does that
- Choosing the detection method that finds the imperfection
Applicability decision flow
| Question | If yes | If no |
|---|---|---|
| Is the parent material aluminium or an aluminium alloy? | ISO 10042 is the quality-level standard for the joint. | Steel, nickel and titanium go to ISO 5817. |
| Was the joint made by an arc welding process? | Stay in ISO 10042. | Beam-welded aluminium joints are graded elsewhere; confirm which standard the application code names before assuming this one covers it. |
| Does the contract or application standard already name a quality level? | Use the level it names. ISO 10042 offers levels; it never selects one. | The application standard selects it, typically through an execution class. Settle that before planning inspection. |
| Do you know the ISO 6520-1 reference number of the imperfection? | Look it up by that number and read the requirement for the selected level. | Classify it in ISO 6520-1 first — the same reference numbers used for steel apply here. |
What proves conformity, and what only supports it
Conformity is decided by inspection and testing against the criteria the standard and the contract set. The records below are evidence that the process was held where it was qualified; they support an inspection result, they never replace one.
| Requirement | Record produced | Source |
|---|---|---|
| Evidence that aluminium's narrow heat input window was held on the welds this standard grades | Arc energy computed per pass from measured current, voltage and travel speed | WeldTrace |
| Interpass control where aluminium's fast thermal conduction hides overheating from the eye | Continuous non-contact interpass temperature measurement on every pass | HeatCam IR-C |
| Targeting inspection effort at the aluminium welds most likely to carry a graded imperfection | Per-weld anomaly flags from a continuous thermal and process record | HeatCore AI |
Evidence the process, not just the paperwork
Therness records what the machine actually delivered on every weld — parameters, thermal signature and a per-weld trail — so a conformity argument rests on measurements instead of recollection.
