PFERD single row standard flag knot wheel brush feature knots that is twisted approximately 75 percent of the Length of the trim. The loosely-twisted knots cover a larger surface area and are ideal for heavy-duty cleaning and surface conditioning. For weld cleaning, weld spatter removal, scale removal, cleaning, deburring, and Flash removal. Specification: arbor hole (inches): 8; arbor hole (inches): 3/4; wire size:.014; trim Length (inches): 1-5/8; face width (inches): 5/8; maximum rotational speed (RPM): 7000.