Abstract: Cutting tool assemblies each of which includes a cutting head attached to the end of a shank holder and a drill adjustably mounted to be moved longitudinally of the shank holder and projecting through the cutting head. In one form the cutting head is a chamfering tool which produces a countersink in the top of the hole in a workpiece bored by the drill. In another form the cutting head is a spot-facing tool which produces an annular flat surface around the hole bored in the workpiece by the drill. The cutting head is fixed to the shank holder and is driven thereby. The drill is clamped to the cutting head so that it is driven with the cutting head by the shank holder. Adjusting means is provided to move the drill axially in the shank holder so that the cutting head completes its cutting operation when a hole of the proper depth is drilled, or shortly thereafter.