Hymnorq 6-Piece Combination Tap And Drill Bit Set With Dual Twist Flute And, 16 Made of high quality 4341 HSS for durability; Suitable for drilling and tapping in plastic, wood and soft metal like aluminum, iron, etc. Drills and taps in a single pass to save your labor and precious time; Point is self-centering and eliminates the need for center drilling or center punching Wide flutes carry the chips out of the hole. Can be used on multi-spindle heads with reversing mechanisms for tapping in most materials 6 imperial sizes of drill and tap bit(1/8?, 5/32?, 3/16?, 1/4?, 5/16?, 3/8?) included in the set to meet your diversified requirements Quick change 1/4" (6.35mm) hex shank with imperial sizes engraved on the tap drills.