... /Competitive price 5.Bright finished Step drill with spiral flute1.) Step drill bits 2.) Spiral flute 3.) Step drill, bright finished 4.)HSS steel ... speed and faster dust rejection.1.) Step drill bits 2.) Spiral flute 3.) Step drill, bright finished 4.)HSS steel 5.) ISO9001 ... ,12,13,14,15,16,17,18,19,20mm88mm11 Step drill with spiral flute