Each SMART-BIT pre-drilling tool, available from Starborn Industries, is designed with a countersink portion that is proportionate to the head of each corresponding screw size. The device matches the head diameter, head angle and countersink depth to provide a good hole and fit. Other key features include a stop collar that spins free of the drill bit and a rubber O-ring intended to ensure the tool stops properly each time without leaving marks. A variety of sizes are available. 800-596-7747, StarbornIndustries.com.