This document provides an American grouping system for materials for welding purposes, classified in accordance with the grouping system of ISO/TR 15608. A number of Canadian, Australian and New Zealand materials commonly used in North America are also included. It can also apply for other purposes, such as heat treatment, forming, and non-destructive testing. Types of steels are listed in accordance with the grouping system of ISO/TR 15608:2017, Table 1. This document covers grouping systems for the following standardized materials: steel; aluminium and its alloys; nickel and its alloys; copper and its alloys; titanium and its alloys; zirconium and its alloys; cast irons.