SIST EN ISO 636:2025 PDF

Overview

EN ISO 636:2024 (ISO 636:2024) specifies the classification of welding consumables - rods, wires and deposits - for tungsten inert gas (TIG) welding of non-alloy and fine‑grain steels. It covers consumables used in the as‑welded and post‑weld heat‑treated (PWHT) conditions for steels with a minimum yield strength up to 500 MPa or a minimum tensile strength up to 570 MPa. The standard is published by CEN/ISO and replaces the 2017 edition.

Key topics and requirements

• Two classification systems:
  • System A - based on yield strength of all‑weld metal and an average impact energy of 47 J (suffix “system A” applies).
  • System B - based on tensile strength of all‑weld metal and an average impact energy of 27 J (suffix “system B” applies).
  • Components without a suffix apply to consumables classified under either system.
• Scope of mechanical requirements: symbols and designation for strength, elongation and impact properties of all‑weld metal.
• Chemical composition: classification includes compositional limits for rods and wires where applicable.
• Testing and verification:
  • Mechanical tests and conditions for classifying consumables (as‑welded and PWHT).
  • Rules for preheating, interpass temperatures and welding procedure during test welds.
  • Rounding procedures, retesting and technical delivery conditions.
• Documentation: the standard provides symbol conventions, classification tables and designation examples to ensure consistent specification and procurement of TIG welding consumables.

Practical applications

EN ISO 636:2024 is used to:

• Specify and select TIG welding filler materials (rods and wires) for non‑alloy and fine‑grain steels where matching weld metal strength and impact properties is required.
• Ensure consistent designation, procurement and quality control of consumables across manufacturers and projects.
• Support weld procedure qualification and material compatibility assessments by providing standardized mechanical and chemical classification data.

Who uses this standard

• Welding engineers and metallurgists specifying consumables for TIG welding.
• Manufacturers of welding rods and wires (product classification and labeling).
• Quality managers, procurement teams and testing laboratories involved in consumable acceptance and certification.
• Standards committees and compliance officers in industries working with non‑alloy and fine‑grain steels.

Related standards

• ISO 544 is cited as a normative reference for delivery conditions.
• EN 1668:1997 is noted as a primary basis for System A classification.
• Prepared by ISO/TC 44 (Welding and allied processes) in collaboration with CEN/TC 121.

Keywords: EN ISO 636:2024, ISO 636:2024, welding consumables, TIG welding, tungsten inert gas, rods, wires, non‑alloy steels, fine‑grain steels, classification, yield strength, tensile strength, impact energy.