Lessmann LES41719811 Knotted Wheel Brush with Shank 75 x 9mm 0.50 Steel Wire Lessmann Knotted Wheel Brushes are fitted with a 6mm shank. Ideal for removing scale rust deburring and roughening. 417.198.11 is an especially narrow brush ideal for working in narrow places. This Lessmann Knotted Wheel Brush has the following specification: Wire Type: Steel Wire Gauge: 0.50 Diameter: 75mm Width: 9mm Shank: 6mm Max Speed: 20,000/rpm