Abstract: A tool driver for rotary cutting tools, such as reamers and drill bits, is described, along with rotary cutting tools of a novel design. The driver comprises a shank member having a cylindrical portion projecting axially from one end thereof and this cylindrical portion has at least two spline members projecting longitudinally from the end thereof remote from the shank. These spline members have curvilinear outer faces forming extensions of the cylindrical portion and also project inwardly to provide a central axial gap and radial gaps therebetween. A cylindrical sleeve member is rotatably mounted on the cylindrical portion and splines and this sleeve member has at the outer ends thereof radially inwardly projecting tab members which are adapted to engage notches in peripheral lands between the flutes of straight flute cutting tools when mounted in the driver.

Abstract: A broaching tool is described having an elongated tool body with an arcuate face of preferably half-round configuration. A plurality of recesses are formed on the arcuate face, each having a bottom face inclined inwardly and rearwardly within 1-15.degree. of coincidence with the longitudinal axis of the body and an abutment wall extending upwardly from a rearward portion of the bottom face. These recesses are arranged in helical paths of preferably increasing diameter in a rearward direction to form a series of spaced helical rows. Each recess contains a rotatably indexable cylindrical cutter disc. This configuration of broach has the advantages of providing excellent chip clearance between the cutters and also providing a uniform load on the tool during broaching.