Abstract: A drilling tool having a cylindrical body with a central axis. A first cutting insert with a cutting edge extending from a datum plane from a position about half way between the central axis and the outer edge of the holes and extending toward the first end of the tool at a first acute angle and a second cutting insert extending from the datum plane extending generally outwardly at a second acute angle substantially less than the first acute angle so that the cutting path of the second insert intersects the cutting path of the first insert whereby four chips are cut by the cutting tool.

Abstract: A drill has a shank with a central axis of rotation and at least one insert on one end of the shank. The insert has at least two cutting edges. The first and second cutting edges cooperate to form a hole when rotated about the central axis. One of the top and bottom faces acts as a seating face and the other acts as a cutting face. Cutting edges are formed on opposite sides of the cutting face. One end of each of the first cutting edges terminates in a juncture with a second cutting edge that extends from the cutting face toward the seating face. The first and second cutting edges cooperate to form a radiused hole when rotated about a central axis. The bottom of said hole is cut continuously across its entire area.

Abstract: A trepanning tool having a hollow, cylindrical body having a central axis with a drive means on one end and a means supporting cutting inserts on the other end. The cutting inserts are arranged to cut in groups of three. Each insert has at least one generally straight cutting edge, the second insert of each said group being disposed generally perpendicular to the central insert, the cutting edge of the first and third insert each being disposed at an acute angle in a vertical plane to the cutting edge of the first insert whereby the three inserts cut a concave circular groove as the tool rotates.

Abstract: A locking device for holding a blade inserted in an axial groove in a cutting body is disclosed. The blades are usually helical and require a locking device that gives line contact between the locking device and the blade since such blades are made of carbide material which is quite brittle and would be distorted and fractured if the blade was contacted over a wide area. The locking devices are frustoconical in shape and have a screw holding them positively in position. The screw has a left hand thread on one end and a right hand thread on the other so that when the screw is rotated in one direction it loosens the clamping device and when it is moved in the other direction it tightens it.

Abstract: A helical cutter in the form of a frustum of a cone having a plurality of cutting inserts supported on its periphery and extending throughout its length. The cutting inserts are in the form of helixes having scallops cut along their cutting edges.

Abstract: A tool having a shank, cartridges on the shank positioned by a screw having two externally threaded parts which engage two internally threaded sleeves which in turn engage threaded openings in the cartridges. One of the threaded openings being right-hand thread and the other opening being left-hand thread. Thus, the cartridges can be moved laterally together or individually by rotating the screw or any of the sleeves.