A cutting tool assembly includes: a cutter body extending perpendicularly from a bottom surface and including a cylindrical portion with a rotational axis; insert pockets disposed and formed concavely in the bottom surface and the cylindrical portion to be spaced apart from each other along a circumferential direction; fixed cutting inserts mounted within the insert pockets and disposed at the outermost portion of the cutter body in a radial direction; and stepped cutting inserts mounted within the insert pockets, the stepped cutting insert being disposed between two adjacent fixed cutting inserts. The fixed cutting insert is disposed to have an identical length from the rotational axis and an identical length from the bottom surface. At least one stepped cutting insert is disposed to have a different length from the rotational axis and a different length from the bottom surface compared to the remaining stepped cutting inserts.

Milling tools and methods are disclosed. The method may include moving a milling tool having at least two axially spaced apart sets of cutting inserts to an axial position within a bore in a material and rotating the milling tool about a longitudinal axis. Contact between the milling tool and a wall of the bore may be initiated in a region of the wall having a least amount of material at the axial position. The milling tool may include a tool shaft having a longitudinal axis, a first set of radially spaced cutting inserts coupled to the tool shaft, and a directly adjacent second set of radially spaced cutting inserts coupled to the tool shaft and spaced from the first set of cutting inserts along the longitudinal axis. The first and second sets of cutting inserts may be staggered from each other by at least 10 degrees.

A rotary tool according to a non-limiting aspect includes a body having a rotation axis and extending from a first end to a second end. The body including: a first part including the first end; a second part located closer to a second end than the first part and having a larger outside diameter than the first part; a cutting edge located at a side of the first end; a ridge portion located in the first part and the second part, connected to the cutting edge and helically extending from the cutting edge toward the second end; and a flute located along the ridge portion. The flute includes: a first flute located at the first part and having a first helix angle; and a second flute located at the second part and having a second helix angle. The second helix angle is smaller than the first helix angle.

Dual cutting milling tools for removing material from a workpiece include two cutting portions, with one cutting portion being configured for ruled milling, and the other cutting portion being configured for hemstitch milling. In this manner, the number of tool changes for a given manufacturing process may be reduced. Dual cutting milling tools include a first cutting portion and a second cutting portion both formed in a shank, with the first cutting portion being configured to perform hemstitch milling on the workpiece, and the second cutting portion being configured to perform ruled milling on the workpiece. Methods of removing material from a workpiece may include both hemstitch milling the workpiece with the first cutting portion of the dual cutting milling tool and performing ruled milling of the workpiece with the second cutting portion of the dual cutting milling tool, without changing tools in the milling machine.

A milling method includes moving a milling tool having at least two axially spaced apart sets of cutting inserts to an axial position within a bore in a material and rotating the milling tool about a longitudinal axis. The method further includes initiating contact between the milling tool and a wall of the bore in a region of the wall having a least amount of material at the axial position. The method further includes moving the milling tool around a perimeter of the bore.

A rotary tool according to a non-limiting aspect includes a body having a rotation axis and extending from a first end to a second end. The body including: a first part including the first end; a second part located closer to a second end than the first part and having a larger outside diameter than the first part; a cutting edge located at a side of the first end; a ridge portion located in the first part and the second part, connected to the cutting edge and helically extending from the cutting edge toward the second end; and a flute located along the ridge portion. The flute includes: a first flute located at the first part and having a first helix angle; and a second flute located at the second part and having a second helix angle. The second helix angle is smaller than the first helix angle.

Dual cutting milling tools for removing material from a workpiece include two cutting portions, with one cutting portion being configured for ruled milling, and the other cutting portion being configured for hemstitch milling. In this manner, the number of tool changes for a given manufacturing process may be reduced. Dual cutting milling tools include a first cutting portion and a second cutting portion both formed in a shank, with the first cutting portion being configured to perform hemstitch milling on the workpiece, and the second cutting portion being configured to perform ruled milling on the workpiece. Methods of removing material from a workpiece may include both hemstitch milling the workpiece with the first cutting portion of the dual cutting milling tool and performing ruled milling of the workpiece with the second cutting portion of the dual cutting milling tool, without changing tools in the milling machine.

A milling method includes moving a milling tool having at least two axially spaced apart sets of cutting inserts to an axial position within a bore in a material and rotating the milling tool about a longitudinal axis. The method further includes initiating contact between the milling tool and a wall of the bore in a region of the wall having a least amount of material at the axial position. The method further includes moving the milling tool around a perimeter of the bore.

Milling tools and methods are disclosed. The method may include moving a milling tool having at least two axially spaced apart sets of cutting inserts to an axial position within a bore in a material and rotating the milling tool about a longitudinal axis. Contact between the milling tool and a wall of the bore may be initiated in a region of the wall having a least amount of material at the axial position. The milling tool may include a tool shaft having a longitudinal axis, a first set of radially spaced cutting inserts coupled to the tool shaft, and a directly adjacent second set of radially spaced cutting inserts coupled to the tool shaft and spaced from the first set of cutting inserts along the longitudinal axis. The first and second sets of cutting inserts may be staggered from each other by at least 10 degrees.

Within examples, systems and methods for forming a hole through at least one layer of a material are provided. An example cutting tool for forming such a hole may include a body, and a first portion of the body having a first diameter and a first radial rake angle. The cutting tool also includes a second portion of the body adjacent the first portion, the second portion having a second diameter and a second radial rake angle, wherein the second diameter is different than the first diameter, and wherein the second radial rake angle is different than the first radial rake angle.