ISO 669:2016 PDF

Overview

ISO 669:2016 - Resistance welding - Resistance welding equipment - Mechanical and electrical requirements - defines the measurable electrical and mechanical characteristics for resistance-welding machines. The standard covers equipment used for resistance spot welding, projection welding, resistance seam welding, upset welding and flash welding, and specifies the information to be supplied in equipment specifications and the test methods for verifying those characteristics. It applies to a range of power-source types (single‑ and three‑phase, rectified or inverter designs) and excludes welding transformers that are separate from the equipment.

Key topics and requirements

• Scope of equipment covered: spot, projection, seam, upset and flash resistance welding equipment.
• Power sources: single‑phase alternating, single‑phase rectified, single‑phase inverter, three‑phase rectified (output and input rectification), and three‑phase inverter transformer systems.
• Electrical characteristics and tests:
  • Rated no‑load voltage (including guidance for inverter types).
  • Maximum short‑circuit current measurements for different equipment types.
  • Thermal rating and thermal testing procedures.
  • Cooling liquid circuit requirements for liquid‑cooled systems.
• Mechanical characteristics and tests:
  • Static mechanical properties: platen stiffness, eccentricity, angular/radial/axial deflection, parallelism and perpendicularity of platens and electrode movement.
  • Machine stiffness and force‑transmission elements (arms, welding heads, electrode holders).
• Specification & documentation:
  • Required content for rating plates (identification, mains supply, welding output, other characteristics).
  • Instruction manual content and tolerances.
• Test conditions & environment:
  • Ambient conditions, humidity, altitude, transport/storage considerations, and measuring instrument requirements.
• What it does not cover:
  • Safety requirements are addressed separately by IEC 62135‑1.
  • Separate welding transformers (not part of the machine) are excluded.

Applications and who uses ISO 669:2016

• Manufacturers of resistance welding machines use ISO 669 to design, rate and document equipment performance and to prepare test reports.
• OEMs and procurement teams in automotive, aerospace, appliance and heavy industries use the standard to set technical specifications and acceptance criteria.
• Test laboratories and quality engineers apply the test methods to verify electrical and mechanical performance during production acceptance or third‑party certification.
• Design and maintenance engineers reference the mechanical tolerances (platen deflection, alignment) to ensure weld consistency, electrode life and process reliability.

Related standards

• IEC 62135‑1 - Safety requirements for resistance welding equipment (design, manufacture, installation)
• ISO 17677 series - Resistance welding vocabulary and measurement methods
• ISO 865, ISO 5184, ISO 5821, ISO 8430 series - Component and electrode standards referenced by ISO 669

Keywords: ISO 669:2016, resistance welding equipment, resistance spot welding, projection welding, seam welding, upset welding, flash welding, welding power sources, mechanical and electrical requirements, welding equipment testing.