ISO 18785-3:2018

Overview

ISO 18785-3:2018 - Friction stir spot welding (FSSW) - Aluminium - Part 3: Qualification of welding personnel specifies requirements for qualifying personnel who set up and operate friction stir spot welding equipment for aluminium and its alloys. It defines who needs qualification (weld setters), what tests and records are required, and the limits of a qualification. Personnel who only load or unload automatic welding units are excluded.

Key topics and requirements

• Scope and purpose: Ensure competent weld setters for FSSW of aluminium to achieve repeatable, defect‑free spot joints.
• Who must be qualified: Weld setters (set up and adjust equipment). Welding operators require equipment operation training as a minimum. Load/unload-only staff are excluded.
• Essential variables that determine qualification ranges:
  • FSSW variant (each variant qualified separately)
  • Welding equipment (type/model and control system changes may trigger re‑qualification)
  • Parent material (qualification is broadly transferable across aluminium alloys, thicknesses, and forms)
  • Weld joint geometry (test in one geometry qualifies others)
• Qualification methods:
  • Standard welding test
  • Welding procedure test (see ISO 18785-4)
  • Pre‑production or production tests
  • Production sample testing
• Test welds and inspection:
  • Tests performed per a qualified WPS (unless otherwise specified)
  • Examiner or examining body witnesses testing; test pieces are identified and marked
  • Visual testing requirements and acceptance levels are referenced (ISO 18785-5)
  • Common imperfections listed include sheet separation, surface imperfections (cracking, lack of consolidation), and excessive flash
• Functional knowledge test: Annex A provides example test topics for equipment functionality and safety
• Certification and validity: Clause 5 covers issuance of qualification certificates, including validity, confirmation and prolongation procedures

Practical applications

• Standardizes personnel qualification for FSSW used in:
  • Automotive and EV body assemblies
  • Aerospace and rail components
  • Marine structures and consumer products
  • Food processing and other aluminium fabrication
• Benefits include consistent weld quality, reduced rework, improved safety, and clear criteria for supplier qualification and audit acceptance.

Who should use this standard

• Welding supervisors and quality managers
• Weld setters and welding operators (training designers)
• Certification bodies and examining authorities
• OEMs, fabricators, and procurement teams specifying supplier competence

Related standards

• ISO 18785-1 (vocabulary)
• ISO 18785-4 (WPS specification and qualification)
• ISO 18785-5 (visual testing of spot welds)
• ISO 17636, ISO 17640 (radiographic and ultrasonic NDT references)

Keywords: ISO 18785-3:2018, friction stir spot welding, FSSW, aluminium, weld setter qualification, welding personnel certification, WPS, visual testing.