This specification covers welded wire reinforcement made from cold-worked drawn or rolled deformed wire, or a combination of deformed and nondeformed wires, to be used for the reinforcement of concrete. Note 1: welded wire for concrete reinforcement has been described by various terms: welded wire fabric (WWF), fabric, and mesh. The wire reinforcement industry prefers the term "welded wire reinforcement" (WWR) as being more representative of the range of products being manufactured. Therefore, the term "welded wire fabric" has been replaced with the term "welded wire reinforcement" in this specification and in related specifications. This specification is applicable for orders in either SI units (M 221M) or in inch-pound units (M 221). SI units and inch-pound units are not necessarily equivalent. Inch-pound units are shown in brackets in the text for clarity, but they are the applicable values when the material is ordered to M 221. Combining values from the two systems may result in nonconformance with the standard.