... .) Step drill, bright finished 4.)HSS steel 5.) ISO9001Step drills are ground from solid high speed steel. A range of hole diameters can ... .) Step drill, bright finished 4.)HSS steel 5.) ISO9001 Step drills are ground from solid high speed steel. A range of hole diameters ... ,12,13,14,15,16,17,18,19,20mm88mm11 Step drill with spiral flute