... .Good quality/Competitive price 5.Bright finished Step drill with spiral flute1.) Step drill bits 2.) Spiral flute ... HSS steel 5.) ISO9001Step drills are ground from solid high speed steel. A range of hole diameters can ... steel 5.) ISO9001 Step drills are ground from solid high speed steel. A range of hole diameters can ... ,24,26,28,30,32mm105mm156-38mm6,9,13,16,19,21,23,26,29,32,35,38mm100mm126-40mm6,11 ...