Weiler 4″ Standard Twist Knot Wire Wheel Brush provides a heavy-duty brushing action with some flexibility for demanding deburring cleaning and surface preparation applications on somewhat irregular surfaces. 3/8″-24 nut for use on right angle grinders. Provide heavy duty brushing action with some flexibility. Ideal for demanding cleaning applications on somewhat irregular surfaces. Knot wire wheels with an arbor hole are intended for use on straight grinders and stationary machines such as bench or pedestal grinders and buffing lathes. Featuring Weiler’s individual knot hole construction, these radial brushes are available in heat-treated steel, type 302 stainless steel and bronze wire for use in a wide variety of applications. .