ISO 14175:2008

Overview

ISO 14175:2008 - Welding consumables - Gases and gas mixtures for fusion welding and allied processes - specifies a harmonized system to classify and designate shielding, backing, process and assist gases used in fusion welding and related processes. The standard covers common processes (per ISO 4063) such as tungsten inert gas (TIG) welding, gas‑shielded metal arc welding (GMAW), plasma welding/cutting, laser welding/cutting and arc braze welding. Its purpose is to help users select the correct shielding gas by chemical properties and metallurgical behaviour and to simplify qualification procedures.

Key topics and technical requirements

• Scope: Applies to gases and mixtures used in fusion welding and allied processes; fuel gases and resonator gases for lasers are excluded. Gases may be supplied liquid or gaseous but are used as gases.
• Classification system: Main groups and subgroups (I, M1–M3, C, R, N, O, Z) based on reactivity and component ranges. Argon/helium are base gases; oxygen, CO2, hydrogen and nitrogen are common components.
• Designation format: Classification + chemical symbols + nominal compositions (e.g., ISO 14175 – M25 – ArCO – 6/4; ISO 14175 – I3 – ArHe – 30).
• Component tolerances: Mixture tolerances are specified (Table 3): for component >5% nominal, ±10% of nominal; for 1–5% nominal, ±0.5% absolute;