These countersinks are designed to drill the pilot hole and countersink or counter-bore for screws in one step. This allows you to countersink to drive the head of the screw flush with or slightly ...

Or, if you are putting in a lot of screws i.e. when building a deck, then use an impact driver ... to use a countersink bit like you'll find in this IRWIN Black Oxide Countersink Drill Bit set ...