ISO 18785-1:2018

Overview

ISO 18785-1:2018 is an international standard published by ISO that provides a comprehensive vocabulary for friction stir spot welding (FSSW) of aluminium and its alloys. This first part of the ISO 18785 series focuses on defining key terminology related to friction stir spot welding processes, equipment, and parameters. Given the growing adoption of FSSW, especially in industries utilizing aluminium structures such as automotive, aerospace, railway, and naval construction, this document facilitates a common understanding and consistency across applications.

The standard details terms that cover the fundamental concepts, tools, welding actions, and process variants, enabling manufacturers, engineers, and welding professionals to communicate effectively and adhere to accepted definitions and practices.

Key Topics

• Friction Stir Spot Welding (FSSW): A solid-state welding process producing discrete lap joints by the frictional heat generated through a rotating tool that softens and stirs the aluminium alloy components without melting.
• Terminology for FSSW Tools:
  • Pion: The rotary pin part of the tool that penetrates the metal.
  • Epaulement: The shoulder of the tool that contacts and forges the metal surface.
  • Bague de serrage (Clamping ring): The non-rotating part holding the workpieces in place during welding.
• Key Welding Parameters:
  • Rotation speed and direction of the tool.
  • Penetration depth and speed of the pin.
  • Force control and tool positioning during welding.
  • Effective rotation time-duration tool remains at maximum penetration before retraction.
• Variants of FSSW Techniques:
  • Conventional FSSW with pin penetration and retraction.
  • FSSW with completion to fill the exit hole.
  • FSSW with translation-short linear or curved movements during penetration.
  • Spiral FSSW involving circular or spiral tool trajectories around the spot.
  • Sweeping FSSW involving discrete angular arcs perpendicular to the surface.
• Roles in FSSW:
  • Operator welder: who operates welding equipment.
  • Welding setter: responsible for configuration and equipment adjustments.
• Quality and Process Control:
  • Ensures welded structures are defect-free through proper selection of materials, design, equipment setup, and monitoring.

Applications

ISO 18785-1:2018 applies primarily to aluminium and its alloys, widely used in manufacturing sectors where lightweight, durable joints are required:

• Automotive industry: Assembly of vehicle body components requiring spot welds for structural integrity and weight reduction.
• Aerospace: Lightweight aluminium alloy fuselage and structural component fabrication.
• Railway vehicles: Welding aluminium carriages and components ensuring safety and durability.
• Food processing equipment: Joining aluminium parts for hygienic and corrosion-resistant surfaces.
• Naval construction: Fabrication of aluminium ship decks and structural elements.
• Consumer products: Durable and reliable aluminium joints in household and commercial goods.

The vocabulary standardized by ISO 18785-1 enables global consistency for process documentation, training materials, qualifications, and technical communications, critical for achieving high-quality welds and optimizing manufacturing workflows.

Related Standards

ISO 18785-1:2018 references and complements several other international standards relevant to welding processes and personnel:

• ISO 25239-1: Friction stir welding-Aluminium-Part 1: Vocabulary. Provides foundational terminology for friction stir welding processes beyond spot welding.
• ISO 14732:2013: Qualification testing of welding operators and setters for mechanized and automated welding. Relevant for personnel qualifications in FSSW.
• ISO/TR 25901-1: Welding and allied processes-Vocabulary-Part 1: General terms. Offers broader welding terminology context.
• ISO/IEC Directives: Governs the development and updating procedures of ISO documents.
• Additional parts of the ISO 18785 series address process specifications, performance requirements, testing methods, and quality assurance for FSSW of aluminium.

Summary

ISO 18785-1:2018 is an essential resource defining the vocabulary for aluminium friction stir spot welding, a critical process enabling robust, high-quality joints in numerous high-value industries. By standardizing terms related to welding equipment, parameters, variants, and roles, it supports clear communication and effective implementation of FSSW technology worldwide.

Key benefits include:

• Facilitating international collaboration and trade by harmonizing terminology.
• Improving process control, quality assurance, and operator training.
• Supporting innovation and consistency in aluminium spot welding applications.

For professionals working with aluminium joining techniques, integrating ISO 18785-1 into their documentation, training, and quality systems ensures adherence to global best practices and enhances product reliability and manufacturing efficiency.