Abstract: The cutting head of a boring tool has a cylindrically arcuate face about the axis of rotation and a radially and axially open groove for release of cooling fluid and chip removal. A single cutting plate is releasably recessed in one wall of the groove and a clamping jaw in the other wall in abutting engagement with the blade whose edge has a primary cutting portion axially projecting from an end portion of the cutting head and a secondary cutting portion radially projecting from the arcuate carrier face.

Abstract: The cutting head and shank of a floating reamer are connected for joint rotation about the shank axis and limited radial movement of the head on the shank by a reduced axial end portion of the shank being spacedly enveloped by an annular axial flange on the head and fastened to the flange by a pin diametrically passing through a bore in the end portion of the shank which is lined with a tubular ball bearing. The clearance between the flange and the end portion of the shank defines the available radial head movement.

Abstract: A conical reamer having an elongated, longitudinally tapering head formed with two longitudinal flutes and rotated about its longitudinal axis by an integral shank portion. An axially elongated groove continuously adjacent each flute is open in a forward, and closed in a rearward direction and receives an axially elongated, reversible cutting blade having a cutting edge exposed in the flute. A frontal end face of the blade diverges obliquely from a plane perpendicular to the reamer axis at one acute angle in a radial direction toward the axis, and at a second acute angle in a direction circumferential relative to the axis. The end face is conformingly engaged in area contact by an abutment face of a clamping ring under the pressure of a clamping screw on the head.

Abstract: The replaceable, annular cutter of a chucking reamer is coaxially centered on the shank by an axial clamping stud partly received in respective bores of the cutter and the shank by engagement of tapering annular faces on the head of the stud and about the bore orifice in the front face of the cutter, the stud being urged inward of the bore by a set screw on the shank engaging an obliquely sloping face of the stud portion conformingly received in the shank bore, the stud being received in the cutter bore with radial clearance.

Abstract: The rotating cutter head of a reamer is formed with a recess, open in a radially outward direction and one circumferential direction relative to the axis of rotation, and a blade is retained in the recess between opposite, radially extending faces of the head and of a clamping shoe that may be adjusted inward of the recess. Two face portions of the blade are engaged by the respective faces of the head and shoe in area contact in planes which converge in a radially outward direction at a small acute angle to prevent movement of the blade from an initial, radially adjusted position under cutting stress.

Abstract: A floating reamer whose cutting head is axially secured to the shank but movable transversely to the parallel axes of the shank and the cutting head toward and away from a position of coincidence of the axes. Pairs of slidably engaged respective guide faces on one axial end of the shank and on the head are parallel and substantially perpendicular to the axes respectively. Two cutting blades project from the cutting head in opposite radial directions and are normally fixed to the head.

Abstract: In a reamer having two diametrically opposite, replaceable cutting blades on its cutter head, an axially elongated rib having a circumferential face approximately cylindrical about the axis of rotation is arranged in each of the two gaps circumferentially bounded by the cutting edges of the blades, thereby assuming the guide function of conventional multiple blades in the reamed hole, and permitting the blade edges to be provided with a relief angle of 5.degree. or more.