Industrial quality HSS. For milling & filing all types of steel, with universal gearing. Long service life High milling performance. Ideal for steel, cast steel, light alloys, brass, copper, bronze & all types of wood. The set comprises: spherical cutter 4mm diam, cylinder cutter 12mm diam, plain cutter 12mm diam & arch pointed cutter 12mm diam, shaft diam 6mm.