A high performance cutting tool for drilling complex holes in a work piece comprising a body having a shank for rotating the tool with a drilling machine, an intermediate flute portion having a plurality of straight flutes formed thereon, and a forward, nose portion. A unitary insert having a plurality of cutting edges formed thereon is received in a slot formed in the cutter tool so as to be driven thereby in a manner which permits cutting of a complex hole in a work piece when the cutting tool is rotated in the work piece.