A tool holder has a tool body with at least one pocket for receiving at least one cutting insert. The at least one pocket has a support surface and an abutment surface transverse thereto, and a first stress relief surface located between the support surface and the abutment surface. The first stress relief surface extends along a first axis towards a first pocket peripheral surface. A second stress relief surface is formed between the first stress relief surface and the first pocket peripheral surface. The second stress relief surface has a convex shape in a cross-sectional view taken in a second plane containing the first axis. The convex shape may have a radius greater than 0.3 mm.

A milling tool has a basic body rotatable about a center axis, and including an outside, which includes a pair of opposite front and back sides, as well as a peripheral envelope surface. The body is equipped with a plurality of replaceable cutting inserts. The basic body includes an inner hollow space having an internal limiting surface, in which there collectively mouth a plurality of bores. The bores also mouth in the outside. Each cutting insert is mounted on an outer end of an ejector, which is rectilinearly movable in the individual bore and has an inner end accessible from the hollow space, and which interacts with a compressible force generator, to pull the same into the bore. By mounting the cutting inserts on ejectors, which simultaneously are accessible from a common hollow space, the cutting inserts can be replaced fast and easily, and possibly also be indexed.

A tool body (12) for a shell end mill (10) is described with at least one helical chip guiding groove (24) arranged at the circumference of the tool body (12) for chip dissipation and at least two receptacles (28) for indexable cutting inserts (26) arranged at the chip guiding groove (24). In this case, the receptacles (28) each comprise a base surface having a bore for receiving an indexable cutting insert fastening screw (34) and at least one first abutment surface adjacent to the base surface. The transition between the base surface and the first contact surface is a groove. In addition, a cutting tool is described with such a tool body, wherein a two-sided indexable cutting insert (26) is attached in each receptacle (28).

A cutting insert mounting system adapted for a cutting tool in which, by using a tightening screw, a cutting insert is detachably mounted on an insert mounting seat. A central axis of a screw hole of the insert mounting seat is inclined with respect to a normal direction of a bottom wall surface of the insert mounting seat. When the cutting insert is placed on the insert mounting seat, on a virtual plane defined to expand the bottom wall surface, a central axis of the screw hole is shifted from the central axis of a through hole of the cutting insert to the side of one of two side wall surfaces of the insert mounting seat. On the virtual plane, an axis shift direction of the central axis of the screw hole and an inclination direction of the central axis of the screw hole are different.

A tool holder has a tool body with at least one pocket for receiving at least one cutting insert. The at least one pocket has a support surface and an abutment surface transverse thereto, and a first stress relief surface located between the support surface and the abutment surface. The first stress relief surface extends along a first axis towards a first pocket peripheral surface. A second stress relief surface is formed between the first stress relief surface and the first pocket peripheral surface. The second stress relief surface has a convex shape in a cross-sectional view taken in a second plane containing the first axis. The convex shape may have a radius greater than 0.3 mm.

A cutting tool assembly has a cutter body, a clamp pin, a cutting insert and a set screw. The clamp pin is inserted to the cutter body to secure the cutting insert to an insert pocket. The set screw is fastened to a threaded hole of the cutter body to press the clamp pin toward the insert pocket. A side surface of the cutting insert contacts a side wall of the insert pocket at a first contact portion. A head of the clamp pin contact an inner peripheral surface of a bore of the cutting insert at a second contact portion. The first and second contact portions are located such that a moment acts on the cutting insert toward the base wall of the insert pocket around the first contact portion.

In a body for a cutting tool having an insert seat, to which a cutting insert is removably attached, not only a structure for preventing a crack at the insert seat, caused by stress concentration, is adopted, but also the cutting insert is stably seated at and firmly attached to the insert seat. A recessed curve portion is formed at a crossing portion between a bottom surface and a wall surface of the insert seat. As viewed in cross section perpendicular to the bottom surface, the cross-sectional shape of the curve portion includes an arc having a radius R of curvature within a range from 0.5-1.2 mm. A height from the bottom surface to a connecting portion between the wall surface and the curve portion is set within a range from 0.1-0.8 mm.

An indexable milling cutting insert includes an opposed outside and inside, a periphery, and a plurality of homologous and alternately individually usable cutting edges, which are equidistantly spaced apart from a center axis, which extends between the outside and inside. The cutting insert includes a plurality of countersunk chip channels, which are delimited by bottoms and tangentially spaced-apart ridges, which individually include a cutting edge formed between a chip surface included in a first chip channel, and a clearance surface, which borders on a second chip channel.

Described herein is an orbital drilling system that includes an orbital drilling machine and a cutter. The orbital drilling machine includes a spindle and an eccentric rotation mechanism. The spindle is rotatable about a cutter axis. The eccentric rotation mechanism is coupled to the spindle and configured to orbit the spindle about an orbital axis, offset from the cutter axis. The cutter is co-rotatably coupled to the spindle and comprises a plurality of cutting edges, collectively defining a cutting diameter of the cutter. The cutting diameter of the cutter is adjustable.

Described herein is an orbital drilling system that includes an orbital drilling machine and a cutter. The orbital drilling machine includes a spindle and an eccentric rotation mechanism. The spindle is rotatable about a cutter axis. The eccentric rotation mechanism is coupled to the spindle and configured to orbit the spindle about an orbital axis, offset from the cutter axis. The cutter is co-rotatably coupled to the spindle and comprises a plurality of cutting edges, collectively defining a cutting diameter of the cutter. The cutting diameter of the cutter is adjustable.