Combination die and tap

Claim 1

A tool for cutting screw threads into a member, comprising: an elongated annular body having a shank at a first end of the body adapted for engagement with a driver to rotate the body in a cutting direction about an axis and a thread cutting portion extending along the body from a second end thereof; the thread cutting portion including a first thread cutting section and a second thread cutting section radially spaced from the first thread cutting section, the first and second thread cutting sections constructed and arranged to simultaneously cut screw threads on concentrically opposed surfaces of the member, the first thread cutting section having a first set of lands with first cutting edges spaced by a first set of flutes and the second thread cutting section having a second set of lands with second cutting edges spaced by a second set of flutes; the first set of lands including first and second subsets of lands, the first subset positioned adjacent the second end of the body, each land in the first subset having a substantially constant radius relative to the axis, and the second subset positioned between the first subset and the first end of the body, each land in the second subset comprising first leading and first trailing contiguous angular segments extending different radial distances from the axis, the first leading angular segment including one of the first cutting edges and the first trailing angular segment forming a recessed region relative to the first leading angular segment and thereby forming a first relieved portion trailing away from the one of the first cutting edges in an angular direction opposite to the cutting direction; and the second set of lands including third and fourth subsets of lands, the third subset positioned adjacent the second end of the body, each land in the third subset having a substantially constant radius relative to the axis, and the fourth subset positioned between the third subset and the first end of the body, each land in the fourth subset comprising second leading and second trailing contiguous angular segments extending different radial distances from the axis, the second leading angular segment including one of the second cutting edges and the second trailing angular segment forming a recessed region relative to the second leading angular segment and thereby forming a second relieved portion trailing away from the one of the second cutting edges in an angular direction opposite to the cutting direction.