Drill Pilot Holes. A pilot hole works in conjunction with a screw-shank clearance hole. ... Combination countersink bits come in various screw sizes (typically 4, 6, 8, and 10) ...

Titex Precision Cutting Tools (www.titex.com) says its XD deep-drilling technology drills holes up to 30 times diameter and at speeds to six-times faster than other technologies. A coolant-fed XD ...

These countersinks bits have a hole in the center that often allows for depth stop and a smaller diameter (pilot) drill bit. They can drill the initial hole and counterbore it.

The drill bits are compatible with ¼-inch hex chucks and SpeedLoad+ connections, while their tip geometry is designed to prevent the bit from moving around as you begin a pilot hole in a variety ...