Overview
EN ISO 18278-3:2017 (ISO 18278-3:2017) specifies standardized evaluation procedures for weldability in spot weld bonding using resistance spot welding combined with adhesive bonding. The standard defines how to determine the acceptable welding current range and to estimate electrode life for prepared assemblies of uncoated and coated metal sheets with individual thicknesses from 0.4 mm to 6.0 mm. It is the CEN-adopted European version of the ISO document and is intended for consistent, repeatable qualification of spot weld bonding processes.
Key Topics
- Scope and purpose: procedures to evaluate weldability for resistance spot weld bonding with adhesive.
- Weld bonding equipment: requirements for electrodes, adhesive dispensing, storage chambers and welding machines.
- Measurement parameters:
- Temperature control
- Amount of adhesive applied
- Welding current and electrode force
- Electrode cooling water flow rate
- Result metrics:
- Weld diameter measurement
- Detection and criteria for expulsion
- Preparation & setup:
- Assembly preparation
- Electrode alignment and conditioning
- Mechanical settings and measurement of parameters
- Test procedures:
- Determination of welding current range (test specimens, parameter selection, pass/fail criteria, multi-sheet stack-ups)
- Electrode life estimation (test specimens, procedure and interpretation of results)
- Reporting: required content for test reports, including current range and electrode life test results.
- Informative annexes: guidance on electrode alignment, current shunt specimens, steel-specific customer qualification, destructive test specimens, and example test reports.
Applications
EN ISO 18278-3:2017 is practical for organizations that need to qualify or optimize spot weld bonding processes, including:
- Welding engineers and process development teams
- Automotive OEMs and suppliers using adhesive-assisted spot welding
- Sheet metal fabricators and electronics enclosures manufacturers
- Quality and materials laboratories performing weldability assessments
- Manufacturers of resistance welding equipment and electrodes
Typical use cases: defining allowable welding currents for a material/coating stack-up, selecting electrode materials and cooling for improved life, documenting qualification for customer or regulatory requirements, and troubleshooting expulsion or inconsistent welds in spot weld bonding.
Related Standards
Keywords: resistance welding, weldability, spot weld bonding, resistance spot welding, welding current range, electrode life, ISO 18278-3, EN ISO 18278-3:2017.
