Overview
EN ISO 9692-3:2016 - "Welding and allied processes - Types of joint preparation - Part 3: Metal inert gas welding and tungsten inert gas welding of aluminium and its alloys" (CEN adoption of ISO 9692-3:2016) specifies recommended joint preparation types and dimensions for MIG (131), TIG (141) and autogenous TIG (142) welding of aluminium and its alloys. The standard applies to fully penetrated welds and provides guidance for commonly used butt-joint forms and edge finishes to achieve reliable aluminium welds.
Key topics and technical requirements
- Scope and processes: Recommendations cover MIG (solid wire), TIG with filler, and autogenous TIG for aluminium. Combinations of these processes are allowed.
- Joint types: Detailed recommended joint preparations (square butt, single-V, single-bevel, single-U, broad root faces, raised-edge butt welds) are provided with reference illustrations and symbols.
- Dimensional guidance: Tables 1–3 list design-limit dimensions (angles, gaps, root-face thickness) for various joint types and plate thicknesses. These are design limits, not manufacturing tolerances.
- Materials: Joint preparations are suitable for weldable aluminium and aluminium alloys.
- Edge finish and cleaning: Edges should be prepared mechanically (shearing, sawing, milling). No mineral oil–based cleaning fluids; if plasma cutting is used, check cut quality (e.g., cracks). Root edges should be de-burred and chamfered for single-sided butt welds without backing.
- Backing and gaps: Larger gaps (≥ 1.5 mm) allow smaller bevel angles; backing is recommended where gaps are ≥ 1.5 mm. For single-sided welding, grooved backing bars are preferred.
- References and symbols: Uses ISO 2553 (weld symbolism) and ISO 4063 (process reference numbers) for consistent representation.
Applications and who should use it
EN ISO 9692-3:2016 is practical for:
- Welding engineers and designers specifying joint geometry for aluminium assemblies
- Fabrication shops and welders preparing edges for MIG/TIG welding of aluminium
- Quality managers and inspectors verifying joint preparation and acceptance criteria
- Manufacturers working with aluminium extrusions and plate assemblies who require standardised butt weld designs
The standard helps ensure consistent weld quality and manufacturability when designing and producing aluminium components using MIG and TIG processes.
Related standards
- ISO 9692 (other parts): Part 1 (steels), Part 2 (submerged-arc), Part 4 (clad steels)
- ISO 2553:2013 - Welding and allied processes - Symbolic representation on drawings
- ISO 4063 - Welding nomenclature and process reference numbers
For implementation, consult the full EN ISO 9692-3:2016 document for complete tables, illustrations and exact dimensional ranges.
