These combination units are specifically designed for woodworkers. The high-speed steel tapered drill bits are precisely ground on a CNC grinder and match the shapes of wood screws so that screw threads grip for the entire length of the screw. Our countersink/counterbore units (unlike most others) are hardened; they are also sharpened after hardening. Used in combination with a stop collar, they let you set the unit for a wide range of screw lengths for everything from flush countersinking to a full 1/2" of counterbore.
The drills are multi-purpose and will serve the needs of most woodworkers for both hard and soft woods. 2 3/4" to 4" long overall. For softwood, you should always use a drill one size smaller than the screw calls for.
The set of five (for screw sizes 5, 6, 7, 8, and 10) contains five countersink/counterbores, five taper-point bits, two stop collars ( 3/8" and 1/2") and two hex keys.
The set of all eight adds the drills and counterbores for screw sizes 9, 12 and 14.
Both sets include a foam-lined plastic storage box with space for additional drivers or bits. Excellent value.