Abstract: A wire for making steel wool has, in cross-sectional profile, a straight top, a pair of sides extending down from said top, and a downwardly and outwardly concave bottom. The sides either taper regularly down from said top toward said bottom so as to impart to said wire a trapezoidal cross-section, or lower portions of otherwise parallel sides taper inwardly at an angle of approximately 20.degree. so that the wire is much narrower at the bottom than at the top. The corners between the sides and the bottom are rounded so as to reduce waste in the production of steel wool. Such a wire is received in a capstan of a steel-wool making machine having wire-holding grooves with central outwardly convex ridges receivable within the concavity in the bottom of the wire.