The Forney 72846 4-Inch Industrial Pro Stringer Bead Twist Knot Wire Wheel Brush is a premium extra narrow brush. Used to clean pipe welds between passes and other applications where a narrow brush face is necessary to do the job. Made from high carbon tempered steel and each tuft is perfectly positioned and set for perfect balance and optimum performance. Patented nut design has gripping points and raised nut making it easier to tighten and loosen on and off angle grinders. Forney Industries is one of America's longest operating family-owned metal working product companies. Founded in 1932, Forney offers more than 5,000 products for the hardware, automotive, farm and ranch and do-it-yourself markets. 4-Inch (101.6-mm) by .020-Inch (0.508-mm) with 5/8-Inch - 11 threaded arbor. Max 15,000-RPM. Claims for warranty must be made within 90 days of the date of purchase. Proof of purchase required. This warranty does not cover any product that has been subject to misuse, neglect, negligence or accident, or that has been used in any way contrary to the purpose intended.