ISO 17633:2025

Overview

ISO 17633:2025 - "Welding consumables - Tubular cored electrodes and rods for gas shielded and non‑gas shielded metal arc welding of stainless and heat‑resisting steels - Classification" - is the 4th edition classification standard for tubular flux‑ and metal‑cored welding consumables used on stainless and heat‑resisting steels. It replaces ISO 17633:2017 (including Amendment 1:2021) and provides a unified classification framework usable worldwide for product designation, documentation and procurement.

This standard defines two parallel classification approaches:

• System A (nominal composition): designation based on nominal all‑weld metal chemical composition; and
• System B (alloy type): designation using traditional alloy‑type codes (three‑ or four‑digit family identifiers).
  Clauses and tables are marked for applicability to System A, System B, or both.

Key topics and technical requirements

ISO 17633:2025 specifies symbols, test requirements and designation rules for tubular cored electrodes and rods, including:

• Product symbol (T for System A; TS for System B) to identify tubular cored consumables.
• All‑weld metal chemical composition symbols and test methods (see Clause 7 and Tables 2–6).
• Core type identification and descriptive tables for flux‑ and metal‑cored constructions (see Clause 5, Tables 9–10 and Annexes B–C).
• Shielding gas and welding position symbols (Clause 5.5 and Table 11).
• Mechanical testing requirements (as‑welded and post‑heat‑treatment conditions), preheat/interpass procedures, pass sequencing (Clause 6).
• Chemical analysis, rounding procedure, retest rules and technical delivery conditions (Clauses 7–10).
• Informative annexes covering alloy comparisons, core descriptions and ferrite considerations (Annexes A–D).

Notable editorial/technical updates in 2025 include reformatted presentation of Systems A/B, updated normative references, added maximum cobalt content (0.50 %) to classifications, and updated alloy compositions and examples.

The standard explicitly does not use pulsed current for classification and does not specify ferrite numbers (see Annex D and ISO/TR 22824).

Applications and users

ISO 17633:2025 is intended for:

• Welding consumable manufacturers classifying tubular cored electrodes and rods for stainless and heat‑resisting steels.
• Welding engineers and fabricators specifying filler materials for gas‑shielded and non‑gas‑shielded metal‑arc welding.
• Quality assurance, procurement and inspection teams creating material data sheets, procurement specs and conformity checks.
• Testing laboratories performing all‑weld metal chemical and mechanical tests to confirm classification.

Practical uses include product labelling, technical data sheets, supplier qualification, and ensuring compatibility of consumables with welding procedures and shielding gases.

Related standards

Normative references include: ISO 544, ISO 6847, ISO 6947:2019, ISO 13916, ISO 14175, ISO 14344, ISO 15792‑1:2020, and ISO 80000‑1:2022. For ferrite guidance, see ISO/TR 22824.

Keywords: ISO 17633:2025, tubular cored electrodes, stainless steel welding, welding consumables classification, gas shielded welding, all‑weld metal composition, shielding gas, welding position.