Overview
ISO/TR 24471:2019 - Brazing - Grouping systems for materials - American materials provides a systematic grouping of American parent materials for brazing qualification. The technical report organizes common US (ASTM) material specifications into material groups to reduce the number of brazing procedure and brazers’ qualification tests required. It mirrors the material-grouping approach used in ISO/TR 20173 for welding of US materials.
Key topics
- Material grouping system - Parent materials are assigned to group numbers (e.g., ferrous 100–180, aluminium 200–220, copper 300–360, nickel 400–430, titanium 500, zirconium 600, magnesium 700, cobalt 800).
- Tables of American specifications - Parent materials are listed by standards body (primarily ASTM) and mapped to group numbers in Tables 1–10.
- Controlling composition rule - Where classification depends on an element’s amount, the controlling value is the maximum content given in the parent material specification.
- Tensile strength basis - Tensile strength values provided in the tables are for the annealed condition. If a minimum tensile strength is not specified, the referencing document establishes that value.
- Substitution guidance - Parent material grouping is intended to minimize qualification testing; however, substitution of one parent material for another (outside qualification purposes) should be made only after evaluating suitability for the intended application. Additional verification tests may be appropriate for some substitutions.
- Administrative notes - The report contains no normative references or explicit terms/definitions and was prepared by ISO/TC 44 (Welding and allied processes), SC 11.
Applications
ISO/TR 24471:2019 is a practical reference for:
- Brazing engineers and metallurgists selecting representative parent materials for procedure qualification.
- Quality and welding/brazing coordinators who aim to streamline qualification testing and ensure traceable material groupings.
- Manufacturers in industries that rely on brazed joints (e.g., heat exchangers, HVAC, automotive components, piping and pressure equipment) when defining brazing procedures tied to American (ASTM) parent materials.
- Training and certification bodies that develop brazing qualification programs consistent with international practice.
Related standards
- ISO/TR 20173 (materials grouping system for welding of US materials) - similar materials-grouping approach.
- Documents and lists maintained by ISO/TC 44 for welding and allied processes may provide complementary guidance.
Keywords: ISO/TR 24471:2019, brazing, materials grouping, American materials, parent materials, brazing qualification, ASTM, tensile strength, substitution guidance.