Weiler 4″ Mini Roughneck Stringer Bead Weld Cleaning Brush is suitable for cleaning root and hot passes and reaching into corners. M14 x 2.0 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. 7/16 in Thikness at face plate. .