This specification prescribes requirements for the classification of carbon steel electrodes (solid, composite stranded, and composite metal cored) and rods (solid) for gas metal arc (GMAW), gas tungsten arc (GTAW), and plasma arc (PAW) welding.

Safety and health issues and concerns are beyond the scope of this standard and therefore are not fully addressed herein. Some safety and health information can be found in the nonmandatory Annex Sections A5 and A10. Safety and health information is available from other sources, including but not limited to ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes, and applicable federal and state regulations.

This specification makes use of both U.S. Customary Units and the International System of Units (SI). The measurements are not exact equivalents; therefore, each system must be used independently of the other without combining in any way when referring to weld metal properties. The specification with the designation A5.18 uses U.S. Customary Units. The specification A5.18M uses SI Units. The latter are shown within brackets [] or in appropriate columns in tables and figures. Standard dimensions based on either system may be used for sizing of electrodes or packaging or both under the A5.18 or A5.18M specifications.