ISO 857-2:2005

Overview

ISO 857-2:2005 - "Welding and allied processes - Vocabulary - Part 2: Soldering and brazing processes and related terms" is an international terminology standard that defines English terms used for metal soldering and brazing and related concepts. It provides clear definitions (with schematic figures) for processes, materials, joint geometry, process conditions and assembly terminology. The standard also includes process descriptions (Annex A) and an alphabetical index giving French and German equivalents for key terms (Annex B).

Key topics

• Scope and classification
  • Distinguishes soldering (filler metal liquidus ≤ 450 °C) from brazing (filler metal liquidus > 450 °C).
  • Covers joining where a molten filler metal wets and is drawn into the joint (capillary attraction).
• Materials
  • Definitions for filler metal, flux, binder, stop-off, parent material, and protective atmospheres (reducing, inert, vacuum).
• Process conditions
  • Key temperature concepts: solidus/liquidus, soldering/brazing temperature, equalizing (preheating) temperature, and effective temperature range.
  • Time-related terms: heating time, holding time, cooling time, total time, and effective time for flux.
• Joint geometry and assemblies
  • Definitions and schematics for closed vs open joints, assembly gap, soldering/brazing gap, lap/butt joints, and dimensions used to describe joints.
  • Terms for assembly regions: solder/braze metal, diffusion/transition zone, heat-affected zone, and soldering/brazing seam.
• Procedures and process types
  • Manual, mechanized and automatic soldering/brazing.
  • Methods such as filler metal applied, filler metal inserted, dip soldering/brazing, and components pre-coated with filler metal.
• Supporting content
  • Annex A: process descriptions organized by energy source (e.g., soldering iron).
  • Annex B: English–French–German term equivalences for brazing/soldering processes.

Applications and users

ISO 857-2 is used to:

• Standardize vocabulary in technical documents, specifications, and quality procedures.
• Support procurement, inspection, manufacturing and maintenance documentation.
• Aid training materials, technical manuals and cross‑language communication (English/French/German). Primary users include welding and joining engineers, brazing/soldering technicians, quality and inspection personnel, technical authors, trainers and standards committees.

Related standards

• ISO 857-1 - Welding and allied processes - Vocabulary - Part 1: Metal welding processes (complements Part 2).
• ISO 4063 - Nomenclature of processes and reference numbers (referenced for process numbering in ISO 857-2).

Keywords: ISO 857-2, soldering vocabulary, brazing terms, filler metal, flux, soldering temperature, brazing processes, joint geometry, soldering standards.