Weiler 4" Stem-Mounted Knot Wire Wheel provides a heavy-duty brushing action with some flexibility for demanding deburring applications on steel, armored steel, cast iron, ductile iron and tool steel. The permanently-attached 1/4 in stem are intended for use on CNC,/Milling/Automatic Machines, Die Grinders, Drills, Drill Presses, Right Angle Die Grinders and Straight Grinders.