Description Milwaukee #6 Countersink features a 9/64" Drill Bit. The bits pre-drill and countersink. The 1/4" Quick Change Hex Shanks allow for quick size changes. The drill bit length is adjustable to allow for precise depth control.PRODUCT DETAIL:Ideal for pre-drill and countersink. #6 Countersink. ¼â Quick change hex shank. 9/64â tapered drill bit. Designed for use in drill drivers.