Abstract: A reciprocating rotary drill bit is disclosed to include a coupling member for coupling the drill bit to a source of drill bit drive power and a cutter member for drilling into a workpiece. The coupling member and the cutter member are slidably associated and include overlapping protruding portions which delimit the upward and downward travel of the cutter member with respect to the coupling member. The slidable association permits reciprocation of the cutter member with respect to the coupling member as the drill bit is rotated into the workpiece. The coupling member also includes protrusions which extend into grooves defined in the cutter member to rotationally secure the two members whereby the cutter member rotates when the coupling member rotates.