Weiler Roughneck 7-inch Root Pass Weld Cleaning Brush with .020-inch Steel Wire Fill and 5/8"-11 UNC Nut 09000Weiler 7" Roughneck Root Pass Weld Cleaning Brush is suitable for cleaning root and hot passes and reaching into corners. 5 8" 11 nut for use on right angle grinders. The standard for high performance weld cleaning brushes Narrow face brushes are suitable for cleaning root and hot passes and reaching into corners Wider face wheels can be used for cleaning filler and cap passes as well as for other surface prep and cleaning applications