Forney Wire Wheel Brush 4 " Twist Knot Quantity of (2): Forney 72759 4", Twist Knot, Wire Wheel Brush Coarse, Arbor 5/8"-11, Wire Size .012", These Wheels Are Used In Surface Preparation Prior To Welding & For Removing Weld Scale, Spatter & Heavy Corrosion Used For Heavy Duty Cleaning Applications.