The Lessmann Knot Wheel Brushes are for grinders, angle grinders and stationary machines, used in the preparation and re-working of bolt fillet and butt welds. They remove scale, rust, paint, slag, rubber residue and can be used for de-burring. They are filled with a special high tensile strength steel wire in order to meet the exacting requirements during use. This Lessmann Knot Wheel Brush has the following specification: Diameter: 100mm. Width: 12mm. Bore: M14. Wire Gauge: 0.50. Wire Type: Steel. Max RPM: 12,500/min.