The Lessmann Wheel Brushes are fitted with a 6mm shank. The tight filling wire and powerful running makes these brushes excellent tools. These encapsulated brushes have a long service life due to the bedding of wire in plastic, which also prevents end breakage. The brushes have a consistent working width. The Lessmann Knotted Wheel Brush With Shank has the following specification: Wire Type: Steel. Diameter: 50mm. Width: 18-20mm. Shank: 6mm. Wire Gauge: 0.30. Max Speed: 15,000/rpm.