Weiler 2-3/4" Single Row Knot Wire Cup Brush provides heavy-duty brushing action with some flexibility. Ideal for demanding cleaning applications on relatively flat surfaces. 5/8"-11 nut for use on right angle grinders. Weiler offers an assortment of wire non-sparking brushes featuring high-quality bronze or brass wire that offer a very soft brushing action in comparison to steel and stainless steel and will not generate a spark when used on metal surfaces. These products are available in a variety of knot wire and crimped wire configurations for use in a broad range of surface cleaning applications, and they are manufactured with individual knot hole and solid ring construction for high performance and long life. Weiler's non-sparking power brushes are available with plain arbor holes, nuts, and permanently attached stems for use on a variety of tools.