5 Point design for quick and clean deburring; 5/16 - 7/8" Range (8-22mm); Single M2-HSS Construction - High Speed Steel is a tungsten-molybdenum high speed steel with a well balanced composition suitable for a wide variety of applications; Perfect for starting a nut on a bolt or threaded bar, a button die or die nut on rod and a leading edge on timber dowel; It efficiently removes burrs and ridges from bolts, pipe, threaded rod, bar and dowels; Threads and burrs are sheared off creating the perfect chamfer for starting a nut or threading die; It is suitable for use on metals including: MILD STEEL - U.S. Grade 2 - Metric Grade 4.8; HARD STEEL - U.S. Grade 5 - Metric Grade 8.8; VERY HARD STEEL - U.S. Grade 8 - Metric Grade 10.9; STAINLESS STEEL - 300 Series; SUPER HARD STEEL - U.S. Grade ASTM-A574 - Metric Grade 12.9; For best results, use a slow drill speed with medium pressure on most materials. Harder materials will require a higher feed pressure.; USE AT LOW SPEED - MAXIMUM 800RPM.; IMPACT DRIVERS WILL REDUCE TOOL LIFE; E-Z CHAMFER (M2-HSS) recommended RPM according to size: 8-12mm (800RPM); 12-18mm (600RPM); 18-22mm (400RPM)