... 1.high quality 2.high speed steel Hss Streight Shank Twist Drill is used to process the hole of steel component ... ,black flute&bright shank,rainbow etc.6. Shank: Straight shank drills, Taper shank drills, 1/2 shank drills,Wood working drill bits, Flat wood ... boring bitApplication:1.drill cast steel2 ...