Knot Cup Brushes are for heavy-duty use for the preparing of metal surfaces before painting and the removal of slag rust scale or concrete waste.Lessmann knotted brushes are filled with a special steel wire of high tensile strength in order to meet the demands of this type of brush. Products marked with a * have a bridle fitted which an be removed to expose a further 20mm of useable wire.Stability bridle fitted.Diameter. 100mm.Bore. M14.Wire Gauge. 0.50.Wire Type. Steel.Max. R.P.M. 8 500.PTDLES486217