HSS Parabolic Flute Drill Bits, DIN338 HSS,HSSCO Fully Ground Deep hole drilling Fast drilling speed & long life HSS Parabolic Flute Drill Bits, DIN338,Material:HSS, HSS CO5%, HSS CO8%Manufacturing Process:Fully Groundparabolic flute drills, deep hole drills, cutting tools, for deep hole drilling on metal, iron steel, cast iron, with split point