Neiko 10218A &frac14;&rdquo; M2 Countersink Bit Set with Carrying Case, 5 Piece | Tri-Flat Shank Set of five 1/4" countersink drill bits with precision-ground 82-degree tips for drilling into wood, soft metals, rubber, plastic, and more Made of high quality M2 material construction for extended bit life and 1/4" shank fits common handheld power drill Five-flute design reduces vibration for smoother drilling and tri-flat shank allows easy gripping Set contains 1/4", 3/8", 1/2", 5/8", and 3/4" countersink drill bits that are very commonly used Sturdy aluminum case with handle included for carrying and storage