This document establishes a European grouping system for materials for welding purposes, classified in accordance with the grouping system of ISO/TR 15608. It is also applicable for other purposes such as heat treatment, forming and non-destructive testing. This document covers grouping systems for the following standardized materials: a) steel; b) aluminium and its alloys; c) copper and its alloys; d) cast irons; e) nickel and nickel alloys. For materials that are not assigned to a group in this document, the criteria of ISO/TR 15608 apply.