Great Design1/4 inch hex shank drill bit is suitable for quick replacement, suitable for most power tools, the cutting edge is hardened and honed for sharpness. All drill bits have a 82 degree angle on the point for sharp and precise countersinking. Easy to UseA chatter-free,five-flute designed with staggered cutting teeth arranged to insure free chip flow and rapid chatter free cutting,reduces vibration for smoother drilling Durable & Long-lifeThe countersink drill bit set is made of industrial grade high carbon steel with hard titanium coating. The automatic center punch is made of pure brass.Durability & Long service life. Size6 different diameter sizes, 6mm(1/4''), 8mm(5/16''), 9mm(3/8''), 12mm(1/2''), 16mm(5/8''), 19mm(3/4''). bullet_point SuitablePerfect for wood openings, reams, chamfers, screw heads, etc. Suitable for chamfering of various soft materials such as wood board, aluminum board, plywood, plastic, PVC board, etc. [Not suitable for metals]