Provided is an end mill which includes an end mill main body having a bottom blade having a convex hemispherical shape, and a hard coating film coated on at least a surface of a distal end portion of the end mill main body. A diameter D (mm) of the bottom blade is 2 mm or less. A ratio W/D of a width W (mm) of a chisel portion to the diameter D (mm) is within a range of 0.020 to 0.060. A ratio L/D of a facing length L (mm) of chip discharge grooves to the diameter D (mm) is within a range of 0.014 to 0.090. A rake angle of the bottom blade in a range in which a chisel edge is formed in the chisel portion is within a range of −15° to −30°.

Provided is an endmill. The maximum spindle speed, per one minute, of a main spindle to which the endmill is attached is Smax. The number of teeth of the endmill is N. The outer shape of the endmill is Da. The natural frequency at which vibrations at the end of the endmill reach a maximum level is ω1. ω1 and/or N are set so that when the diameter-direction infeed amount of the endmill is set to Rd: i) ω1×60/N×6<Smax, if Rd is at least 4% of Da; and ii) ω1×60/N×3<Smax, if Rd is less than 4% of Da.

A processed article is manufactured with a tool including a cutting blade. The cutting blade is arranged to be in contact with two machined segment surfaces so that two contact points are defined between the two machined segment surfaces and the cutting blade in a corner. A machining pitch is set in a pick feed direction of the tool at the corner to a first machining pitch for when a part of the cutting blade corresponding to a projected shape of a side surface of the cutting blade having a first curvature radius is a cutting point. A cut is performed along a feed direction in the two adjacent machined segment surfaces successively at the corner so that the tool proceeds toward the corner in one of the machined segment surfaces and away from the corner in the other one of the machined segment surfaces.

Provided is an end mill which includes an end mill main body having a bottom blade having a convex hemispherical shape, and a hard coating film coated on at least a surface of a distal end portion of the end mill main body. A diameter D (mm) of the bottom blade is 2 mm or less. A ratio W/D of a width W (mm) of a chisel portion to the diameter D (mm) is within a range of 0.020 to 0.060. A ratio L/D of a facing length L (mm) of chip discharge grooves to the diameter D (mm) is within a range of 0.014 to 0.090. A rake angle of the bottom blade in a range in which a chisel edge is formed in the chisel portion is within a range of −15° to −30°.

A processed article is manufactured with a tool including a cutting blade. The cutting blade is arranged to be in contact with two machined segment surfaces so that two contact points are defined between the two machined segment surfaces and the cutting blade in a corner. A machining pitch is set in a pick feed direction of the tool at the corner to a first machining pitch for when a part of the cutting blade corresponding to a projected shape of a side surface of the cutting blade having a first curvature radius is a cutting point. A cut is performed along a feed direction in the two adjacent machined segment surfaces successively at the corner so that the tool proceeds toward the corner in one of the machined segment surfaces and away from the corner in the other one of the machined segment surfaces.

A mold is configured to resin-seal a semiconductor chip to form a semiconductor package. The mold has a first mold cavity and a second mold cavity formed in the bottom of the first mold cavity with a stepped portion between the two mold cavities. The two mold cavities are formed in succession by a high-speed rotary cutter having a downwardly tapered round cutting surface that imparts a corresponding taper to walls of the two mold cavities.

Provided is an endmill (5). The maximum spindle speed, per one minute, of a main spindle to which the endmill is attached is Smax. The number of teeth of the endmill (5) is N. The outer shape of the endmill (5) is Da. The natural frequency at which vibrations at the end of the endmill (5) reach a maximum level is 1. 1 and/or N are set so that when the diameter-direction infeed amount of the endmill (5) is set to Rd: i) 160/N6<Smax, if Rd is at least 4% of Da; and ii) 160/N3<Smax, if Rd is less than 4% of Da.

An attrition liner machining tool, configured to machine the surface of an attrition liner provided radially outward of a set of a plurality of fan blades in a gas turbine engine. The tool includes at least one rotating machine tool having a connector at a first end and a cutter at a second end. The connector is configured to rigidly connect to a rotating fan blade mount of the gas turbine engine that, in use of the gas turbine engine, supports the fan blades. The cutter is configured to machine the attrition liner. The at least one rotating machine tool is configured such that, when it is connected to said rotating fan blade mount of a gas turbine engine, the cutter is passed across the surface of the attrition liner when said rotating fan blade mount is rotated.

Provided is an endmill. The maximum spindle speed, per one minute, of a main spindle to which the endmill is attached is Smax. The number of teeth of the endmill is N. The outer shape of the endmill is Da. The natural frequency at which vibrations at the end of the endmill reach a maximum level is 1. 1 and/or N are set so that when the diameter-direction infeed amount of the endmill is set to Rd: i) 160/N6<Smax, if Rd is at least 4% of Da; and ii) 160/N3<Smax, if Rd is less than 4% of Da.