A whirling tool for machining a workpiece, having: three or a multiple of three cutting plates, wherein each of the cutting plates comprises at least one cutting edge; a cutting plate holder having a plurality of cutting plate receptacles, wherein each of the cutting plate receptacles is configured to receive one of the cutting plates, wherein the cutting plate receptacles are disposed so as to be distributed in a circumferential direction across the cutting plate holder; and a plurality of fastening elements for releasably fastening the cutting plates in the cutting plate receptacles of the cutting plate holder; wherein the cutting plates comprise at least two different kinds of cutting plates, wherein at least one cutting plate of a first kind, and one cutting plate of a second kind are provided for each group of three cutting plates that are disposed beside one another on the cutting plate holder, wherein the cutting plate of the first kind differs from the cutting plate of the second kind by an overall geometry, by a dimension of the at least one cutting edge, and by a shape of the at least one cutting edge.

A whirling tool for machining a workpiece, having: three or a multiple of three cutting plates, wherein each of the cutting plates comprises at least one cutting edge; a cutting plate holder having a plurality of cutting plate receptacles, wherein each of the cutting plate receptacles is configured to receive one of the cutting plates, wherein the cutting plate receptacles are disposed so as to be distributed in a circumferential direction across the cutting plate holder; and a plurality of fastening elements for releasably fastening the cutting plates in the cutting plate receptacles of the cutting plate holder; wherein the cutting plates comprise at least two different kinds of cutting plates, wherein at least one cutting plate of a first kind, and one cutting plate of a second kind are provided for each group of three cutting plates that are disposed beside one another on the cutting plate holder, wherein the cutting plate of the first kind differs from the cutting plate of the second kind by an overall geometry, by a dimension of the at least one cutting edge, and by a shape of the at least one cutting edge.

An internal milling cutter includes a carrier disk having a centre axis defining an axis of rotation of the milling cutter, a plurality of separated tool holder segments removably mounted at the inner circumference of the carrier disk, and at least one clamp for each tool holder segment mounted either on the carrier disk or on the tool holder segment. Each of the tool holder segments at its inner circumference includes at least one cutting insert seat with a mounting element for a cutting insert or at least one cutting edge. The clamp is located and arranged such that it generates a force in the axial direction pressing the axial contact surface of the tool holder segment onto the axial abutment surface of the carrier disk, and the clamp is mounted movably in a radial direction of the carrier disk between a locking position and a releasing position.

An internal milling cutter includes a carrier disk having a centre axis defining an axis of rotation of the milling cutter, a plurality of separated tool holder segments removably mounted at the inner circumference of the carrier disk, and at least one clamp for each tool holder segment mounted either on the carrier disk or on the tool holder segment. Each of the tool holder segments at its inner circumference includes at least one cutting insert seat with a mounting element for a cutting insert or at least one cutting edge. The clamp is located and arranged such that it generates a force in the axial direction pressing the axial contact surface of the tool holder segment onto the axial abutment surface of the carrier disk, and the clamp is mounted movably in a radial direction of the carrier disk between a locking position and a releasing position.

A rotary cutting tool having a disk-shaped cutting body with a plurality of identical insert receiving pockets, and an equal number of indexable cutting inserts removably retained therein, having opposing upper and lower surfaces and opposing first and second insert end surfaces. First and second cutting edges are formed at the intersection of the upper surface and the first and second insert end surfaces, respectively. Circumferentially adjacent cutting inserts have a different one of their first and second insert end surfaces in contact with an insert receiving pocket back wall. First and second planes are equidistantly offset from opposite sides of the cutting body, the first plane only intersecting the first cutting edge of every circumferentially alternate cutting insert and none of the second cutting edges, and the second plane only intersecting the second cutting edge of every circumferentially alternate cutting insert and none of the first cutting edges.

A rotary cutting tool having a disk-shaped cutting body with a plurality of identical insert receiving pockets, and an equal number of indexable cutting inserts removably retained therein, having opposing upper and lower surfaces and opposing first and second insert end surfaces. First and second cutting edges are formed at the intersection of the upper surface and the first and second insert end surfaces, respectively. Circumferentially adjacent cutting inserts have a different one of their first and second insert end surfaces in contact with an insert receiving pocket back wall. First and second planes are equidistantly offset from opposite sides of the cutting body, the first plane only intersecting the first cutting edge of every circumferentially alternate cutting insert and none of the second cutting edges, and the second plane only intersecting the second cutting edge of every circumferentially alternate cutting insert and none of the first cutting edges.

A compression milling cutter includes a shank and a front cutting portion that terminates at a leading end of the milling cutter. The front cutting portion has a first circumferential row of one or more insert receiving pockets proximate a leading end of the milling cutter, and a second circumferential row of one or more insert receiving pockets, each insert receiving pocket configured to receive a respective indexable cutting insert. The cutting insert mounted in the first circumferential row has a positive axial rake angle, A, and the indexable cutting insert mounted in an insert pocket of the second circumferential row has a negative axial rake angle, B. Because of the different axial rake angles, chips generated during a machining operation flow in opposite directions, thereby creating a compression zone disposed between the first and second circumferential rows. This compression zone replicates the cutting action of a solid end mill, particularly when machining fiber reinforced plastic materials.

A first main trajectory represents a trajectory of a first main cutting edge obtained by revolving and projecting the first main cutting edge onto a plane including a central axis. A second main trajectory represents a trajectory of the second main cutting edge obtained by revolving and projecting the second main cutting edge onto the plane. The first main trajectory intersects the second main trajectory. A tangent to the first main trajectory at an intersection between the first main trajectory and the second main trajectory is inclined to be closer to the central axis in a direction from the first surface toward the second surface. A tangent to the second main trajectory at the intersection is inclined to be closer to the central axis in a direction from the second surface toward the first surface.

A first main trajectory represents a trajectory of a first main cutting edge obtained by revolving and projecting the first main cutting edge onto a plane including a central axis. A second main trajectory represents a trajectory of the second main cutting edge obtained by revolving and projecting the second main cutting edge onto the plane. The first main trajectory intersects the second main trajectory. A tangent to the first main trajectory at an intersection between the first main trajectory and the second main trajectory is inclined to be closer to the central axis in a direction from the first surface toward the second surface. A tangent to the second main trajectory at the intersection is inclined to be closer to the central axis in a direction from the second surface toward the first surface.

The embodiments described herein relate generally to improved fit duct liner insulation for curvilinear ducts in HVAC, exhaust, or other similar gas flow systems. A duct liner insulation for a curvilinear duct may include an insulation board having a first major surface and a second major surface. The duct liner insulation further includes a plurality of rows of kerfs in the first major surface of the insulation board configured to allow the insulation board to flex in a direction of the width of the insulation board such that insulation board is foldable into a curvilinear configuration. Each of the kerfs has a v-shaped cross section with sidewalls extending from a kerf base portion at or near the second major surface of the insulation board to the first major surface of the insulation board. The sidewalls extending at an angle from 10 degrees to 20 degrees relative to each other.