Overview
EN ISO 16433:2007 (ISO 16433:2006 adopted by CEN) specifies a procedure and requirements for resistance seam welding of uncoated and metallic-coated low carbon steels. It applies to assemblies of two sheet components where the maximum single-sheet thickness is 0.4 mm to 3 mm. Covered surface types include uncoated steels and metallic coatings such as hot-dip zinc/galvannealed, electrolytic zinc/zinc-iron/zinc-nickel, aluminium-coated, and zinc‑aluminium steels. Organic- or primer-coated steels are excluded.
Key Topics
- Scope and applicability: Seam welding of two-sheet assemblies of low carbon steel (0.4–3 mm), listing applicable coated and uncoated surface conditions.
- Process types: Continuous-current seam welding and interrupted-current (pulsed) seam welding; also describes mash seam, wire seam and wide-electrode seam techniques.
- Welding equipment and electrodes: Guidance on welding machine characteristics, electrode (wheel/mandrel/pad/backing bar) materials, dimensions and cooling requirements.
- Materials and surface preparation: Requirements for flat-rolled steel form, acceptable surface conditions, and limitations on coatings.
- Weldability and procedure development: Methods to determine weldability lobes and to select welding parameters adapted to machine and production conditions.
- Type and routine testing: Mandatory test methods include manual peel, mechanised peel, pressure tests, metallurgical and visual examinations, and geometric weld measurements. Acceptance criteria and failure-mode assessment are defined.
- Quality control and production: Routine checks for nugget width, weld dimensions, appearance, failure modes and distortion; guidance for reclaiming non-conforming assemblies.
- Informative annexes: Annex A (equipment guidance), Annex B (typical seam welding conditions), Annex C (partial list of applicable steel grades).
Applications
Who uses EN ISO 16433:2007:
- Welding engineers and procedure writers developing welding procedure specifications (WPS) for seam welding.
- Quality managers and inspectors performing routine weld testing (peel, pressure) and acceptance checks.
- Fabricators in industries that seam-weld coated or uncoated low carbon sheet: automotive body panels, white goods/appliances, HVAC ducting, light-gauge construction, and general sheet-metal manufacturing.
- Machine manufacturers configuring equipment (wheel electrodes, cooling, controls) for consistent resistance seam welding production.
Practical value: ensures repeatable, verifiable seam weld quality for coated/uncoated low-carbon steels, assists compliance with industry-specific WPS and helps reduce production defects from poor electrode choice, incorrect parameters or unsuitable surface conditions.
Related Standards
Normative references commonly used with EN ISO 16433:
For applications requiring certified procedures, consult EN ISO 16433 alongside these referenced standards when preparing welding procedure specifications and quality plans.