An end mill includes: a columnar tool body that rotates about a center axis; and outer peripheral cutting edges on an outer peripheral surface of the tool body, the outer peripheral cutting edges including a first outer peripheral cutting edge and a second outer peripheral cutting edge. A relief angle θ of the first outer peripheral cutting edge changes to increase in an axial direction of the tool body from a bottom face that is one end of the tool body. A relief angle θ of the second outer peripheral cutting edge changes to decrease in the axial direction from the bottom face.

A rotary tool can be adapted for removing material from a workpiece such as a lower receiver. A rotary tool can have an adapter with a major diameter, and a cutter head with a minor diameter. The major diameter of the adapter can reduce deflection and chatter, while the minor diameter of the cutter head can be used to manufacture lower receivers with accuracy. The rotary tool can be adapted to be engaged with a rotary power tool.

A rotary tool can be adapted for removing material from a workpiece such as a lower receiver. A rotary tool can have an adapter with a major diameter, and a cutter head with a minor diameter. The major diameter of the adapter can reduce deflection and chatter, while the minor diameter of the cutter head can be used to manufacture lower receivers with accuracy. The rotary tool can be adapted to be engaged with a rotary power tool.

A cutting tool includes a substrate of cemented carbide including hard constituents in a metallic binder. The hard constituents includes WC and the WC content in the cemented carbide is 80-96 wt%. The cemented carbide has a Ni content of 2.5-13 wt%, a weight ratio of Fe / Ni < 1.5 and a weight ratio of Co / Ni < 0.825. The cutting tool includes a rake face, a flank face and a cutting edge there between, wherein the hardness H is measured with Vickers indentation and the crack resistance W is the ratio of the load to the total crack lengths of the cracks in the corners of said Vickers indentation. The product of the hardness at the rake face H(rake) and the crack resistance at the rake face W(rake) for the cutting tool is H(rake)*W(rake) > 2000 HV100*N/.Math.m.

A milling insert for a side and face milling tool includes an upper side defining an upper extension plane, a lower side defining a lower extension plane, and a side surface extending between the upper and the lower sides around a periphery of the insert that includes a main radial clearance surface, two opposite axial clearance surfaces and two corner clearance surfaces. At least one cutting edge is formed in a transition between the upper and the side surfaces, wherein each cutting edge includes a main cutting edge extending above the main radial clearance surface and two corner cutting edges extending above the corner clearance surfaces on opposite sides of the main cutting edge. The main cutting edge slopes downward toward a midpoint of the main cutting edge and the main cutting edge and the main radial clearance surface slope outward from the corner cutting edges toward the midpoint.

A cutting insert includes an upper surface, a lower surface opposite to the upper surface, a first side surface and a second side surface configured to connect the upper surface and the lower surface, a mounting hole formed to penetrate the upper surface and the lower surface, a first cutting edge formed at an edge of the upper surface that meets the first side surface, and a second cutting edge formed at an edge of the upper surface that meets the second side surface. The lower surface includes a ridge portion, and a first inclined surface and a second inclined surface positioned on both sides of the ridge portion as a boundary. When looking at the lower surface, the first inclined surface and the second inclined surface have asymmetric shapes with respect to the ridge portion.

A height milling device is provided, which has a base platform with a working surface and at least a height milling component displaceably disposed on the working surface for performing a height machining on a target object, thereby speeding up the production, improving the production efficiency and reducing the labor cost.

A height milling device is provided, which has a base platform with a working surface and at least a height milling component displaceably disposed on the working surface for performing a height machining on a target object, thereby speeding up the production, improving the production efficiency and reducing the labor cost.

Milling tool holder which comprises a first holder part, a second holder part, and a locking mechanism. The first holder part comprises a first cutting insert receptacle for receiving a first cutting insert and a second cutting insert receptacle for receiving a second cutting insert. The second holder part which, for adjusting a milling width, is variably positionable with respect to the first holder part along a longitudinal axis, comprises a third cutting insert receptacle for receiving a third cutting insert and a fourth cutting insert receptacle for receiving a fourth cutting insert. The locking mechanism is configured to fix the first and second holder parts to the adjusted milling width. The first holder part and the second holder part are positioned with respect to one another in such a manner that the third cutting insert receptacle is arranged in the circumferential direction between the first cutting insert receptacle and the second cutting insert receptacle, and that the second cutting insert receptacle is arranged in the circumferential direction between the third cutting insert receptacle and the fourth cutting insert receptacle.

A tool (T) is provided with: a shaft-like tool body (11) having a first end portion (11a) extending along a central axis line (Ot) and attached to a main shaft, and a second end portion (11b) on an opposite side to the first end portion (11a); and a fore end portion (12) connected to the second end portion (11b) of the shaft-like tool body (11). The fore-end portion (12) includes a central portion (13) including a fore-end face (17) of the tool (T), and a plurality of blade portions (14) protruding radially outward from the central portion (13). A cutting blade of each blade portion (14) includes a main cutting blade (15) adjacent to the fore-end face (17). The main cutting blade (15) includes an outline that forms an angle of 30-150 degrees with respect to the central axis line (Ot) in a cross-sectional view including the central axis line (Ot).