0.4mm Micro HSS Drill Bit, 10 Pack

High speed steel (HSS) is a form of tool steel. HSS bits are hard, and much more resistant to heat than high carbon steel. They can be used to drill metal, hardwood, and most other materials at greater cutting speeds than carbon steel bits, and have large HSS mini Jobber Drills (twist drills) in handy packs of 10 pieces Straight shank Suitable for use in hand held drill holders